The problem is that your child might have SIDS - sensory integration disorder. And dealing with that is very different then just dealing with a picky eater. I highly suggest you repost to our SIDS site -
http://www.medhelp.org/forums/Sensory-Integration-Disorder-SID/show/1396
Specialmom who is the CL for the site has dealt with this with her own son and has lots of good practical advice. You also might want to check out this site to see if she has any others symptoms - http://www.sensory-processing-disorder.com/sensory-processing-disorder-checklist.html
And speaking as someone who is also the CL for the ADHD forum, attention getting behavior at the table for someone of this age is kind of normal. You mentioned the possibility of ADD. I know that she has not been in kindergarten very long, but what do her teachers say about her ability to pay attention? I have seen many posts about eating problems of ADHD kids, but typically it is due to the stimulant medications they are taking. I really haven't seen much written anywhere about problems of eating caused by ADHD - doesn't mean its not possible. But, it is important to know if she is on any meds. Also curious if the eating problems are only at dinner. How does she do at lunch and breakfast?
I really understand where you are coming from. Having a child born at 30 weeks makes one extremely protective. And I am sure that you are even more aware/concerned of her eating habits due to the desire to see her thrive. And, it possible that you may have gone a bit overboard - which would be very understandable. I think that you need to figure out first it what is something driving this. Its really hard to treat something if you don't know the cause.
Second, I am a big fan of timeouts (if used correctly). But, I can't think of anyway that a timeout would help a food eating situation. For a timeout to be used effectively it must be done immediately. Which means that if the child is not eating - she goes into a timeout - which means she does not have to eat? And if its done after the meal - it won't work! So I really think that you should post to Specialmom on the SIDS forum. I have seen her post lots of very good ways to deal with eating that will work even if she does not have SIDS.
There really is a lot going on here. Apparently, you are seeing a psyc which is good. I do wonder if you have any other kids (just to eliminate that distractor).
You asked, "how to you address a child who doesn't eat because there are more interesting things going on?" The real question is - is she not eating because of more interesting things going on - or is she not eating because of other reasons mentioned above? So far we probably have more questions then answers, but ya gotta start somewhere. Best wishes.