Let me address both the boy's condition and the custody and visitation arrangement.
Relative to the youngster's condition, it represents both neurointegrative and emotional disorders. He may well display ADHD, given the prominence of overactivity and impulsivity. Apparently he is more organized in the school setting, by virtue of the standardized feedback from the teacher. That is, he/she apparently did not endorse a sufficent number or range of symptoms to make an unambiguous judgement. Suffice it to say that an evaluation by a mental health professional is in order.
Alongside what is likely ADHD is a level of personality disorganization that is alarming, even in a child so young. At the very least, what you are witnessing is a range of developmental lags or delays, probably exacerbated by the family situation. But it is possible that this child displays a Pervasive Developmental Disorder (a broad spectrum of conditions) that requires professional intervention. He should be evaluated by a team of developmental specialists, including developmental pediatrician, developmental/clinical psychologist and child psychiatrist. In addition, the family situation should be evaluated as part of the process, and the most appropriate professional to conduct such an evaluation is a clinical social worker.
Relative to the custody arrangement, I infer from your description that, by the term 'shared biweekly visitation' you mean that the children spend one week with their mother and then one week with their father. Is this correct? Or do you mean that the children 'visit' on alternate weekends. If the former is true, it is an inappropriate custody arrangement. It obviates the sort of structure, routine and stability that all young children require. To tell you the truth, most such arrangements, in my opinion, are more conducive to meeting the needs of parents than they are of meeting the needs of the children. Now, to some extent the particulars of a custody arrangement depend on the capacity of each parent. Hopefully, the children will spend the preponderance of their time with a parent who is stable, mentally healthy and capable of sound parenting. So it is hard to talk in generalities about such an issue, but in a general 'rule of thumb' way an arrangement that calls for children to spend alternate weeks with each parent is not sensible (even when both parents are capable). The 50/50 shared custody arrangements are too new for there to be research which might indicate, in a longitudinal way, the impact. Those of us who see hundreds of children in these situations are very wary of them (in a way we might not be for older children, depending on the particulars). Another very reliable rule of thumb is that the more disturbed a child is at baseline, the worse it is for them to encounter so many transitions in their lives.
If the arrangement is alternate weekends, that would be more satisfactory. In other words, it would reflect another 'rule of thumb', i.e., that young children should have a principal residence.
Your presence or absence in the home really depend more on your ability to manage the situation than on anything else. In an ideal way, since you are a member of father's household, you should be there. However, it's a less-than-perfect world, and if you are not able to manage the stress occasioned by parenting this child, that's OK. He can experience your involvement in any way you and his father agree is sensible. Whatever you decide, try to be consistent - back and forth, unstable arrangements are not good for children for the very reason that they benefit from stable, routine, consistent adult presence.
It's understandable why you wanted to convey your information via several postings. This is a very demanding child to parent. While ADHD may be part of his makeup, it's not by any means the most central piece. Hopefully his parents can arrange the sort of evaluations I detailed above.
Regarding my presence: I do not live in the home, I have my own apartment. C is used to seeing me anywhere from 2 to 4 times a week. When I'm not around, he tells BF he misses me and asks when does he get to see me and tells BF to tell me he misses me. In light of this, does taking it down to a once a week outing still sound in C's best interest? I just want to do what's right for him. I don't want him to suffer anymore unnecessarily. I can handle him okay if I get breaks in between the days I go visit, but it is quite demanding simply because it's a constant, 24/7 interaction (not to mention that I work full time, attend college full time, and am a single mom!). Sometimes I feel like me being there just makes it harder on C because he's not used to the instability he deals with on a regular basis already and I'm just one more factor in the mix. This is why I felt like it would be better for me to meet them at the movies or an outing away from the home, consistently once a week. Aside from the frequency issue, do you think it makes any difference if it's away from the home or not?
Another concern is a fear that BF and my relationship won't make it. I don't want C's life disrupted anymore than it has to be. I want this relationship to work, but it so incredibly difficult for me to watch C suffer so.. and although the father is seeking medical assistance for C (now that we've gotten a response), he hasn't mentioned changing visitation and it's becoming increasingly difficult to consider staying in a relationship and watching C flail, and to think about the impact on C's future - and to know that it's because neither parent is adult enough to do what's right for the child. It angers me and is actually starting to cause problems in the relationship, mainly because I have the same outlook that you do on the bi-weekly visitation, particularly with a child so young and with the issues that have already arisen thus far. As long as I see BF striving toward what's best for C, I will give it my all, but I will have a difficult time staying in a relationship with someone who doesn't put their child's best interest above their own. I know if he truly felt like this visitation was wrong for C, he would have it changed, but I think he feels the root is the actual divorce, not the visitation. I'm not sure how to help him to understand, that's why I was hoping to find some case studies or research.
If you wouldn't mind, I'd really appreciate a response to the frequency and location issues on my involvement in C's life now that you know I don't live in the home. I'm not trying to be "self-centered".. I just want to make sure that my actions don't have a negative impact on that child's life.. he's so attached to me, it scares me.. or that if I do end up leaving the relationship, the negative impact on the children is as minimal as possible... he suffers enough already.
Again, thank you a tremendous amount for your response.. and know that your involvement here is changing lives; because of this site, a little boy will finally get the help he so desperately needs!
There is no right/wrong re: your relationship with the family. On the personal front, it's important to realize your limits, and proceed in a manner that permits you to have some fulfillment. Your decision needs to be based on what serves your relationship with your boyfriend. If you base it on the child's best interest or on what the boy prefers, you might be acting in a way that impedes your relationship with your boyfriend. You may well settle this issue in a manner different from what you might if you were making a decision about your biological child. Whatever you decide, try to settle on a consistent interaction (as it involves the boy). The fact that he can 'count on' some frequency or type of inclusion on your part is as important as the specifics of the frequency. Remember: structure (i.e., routine, predictatble contact) is the key. The specifics should depend, more than anything, on the personal relationship between you and the boy's father.
I hope that many parents considering shared custody or shared visitation run across this posted thread during research of their decision. The whole thing reminds me of the story in the Bible of King Solomon and the dispute between the two mothers. The REAL parent of the baby was willing to sacrifice her own desires (although excruciatingly painful) for the best interest of her child.
At any rate, your suggestions are a great help and I will take them to heart when considering my choices and making my decisions.
Again, I can't thank you, the other volunteers, and the founders of this website enough. You all are doing good work. Best wishes.