treatment options for arrythmia

It seems I always have new questions, but here goes again.  I am 33, and troubled by arrythmias since my pacemaker was put in for SND. A-fib is the most prevalent. I take amiodarone, cartia, coumadin, lasix, midodrine. One month ago my EP doc programed my pacer to record ventricular events, and when I went in last week for the interrogation my doctor was surprised. He said I only had 30 episodes of a-fib, but hundreds of v-tach, with rates at times over 300bpm. Yes, I do feel these.  I have collapsed a couple of times, not completely passed out, but I lose my vision and get extremely weak and sweaty, and I can't stand.

My doctor had talked about doing an av node ablation, but now says with v-tach that wouldn't be prudent. He doubled my dose of amiodarone, and cartia. I already have liver toxicity. So my questions are
1) Could these v-tach episodes turn into a dangerous rhythm?
2) When do you decide to call 911?
3) Is a-fib somehow related to v-tach?
4) Why would I suddenly develop this rhythm?
5) Can ablations be done for all of these?
6) Could you share any ideas for what I could do for treatment?
7) Is a defibrillator required for v-tach?
Sorry so much.  I am trying to be as informed as possible. I deep respect my doctor, but different opinions are great. Thank you so so much.

[CCF-M.D.-CRC]

Dear cn,
As I have suggested before I think you need to get a second opinion from a major EP center.  Your case is very complex and you probably require several different ablations in addition to a possible upgrade to an ICD.  If you would like to come to Cleveland I would recommend Dr. Bob Schweikert or Dr. Natale.  Otherwise if you can tell me what major city you are close to I can see if I know somebody there.  In the meantime I would suggest calling (or having someone else call) 911 anytime you pass out or are having rapid, sustained tachycardia.