The success of an ablation depends on alot of things, but the average is something like 85 - 90% [I think that's from the American Heart Association, I'll have to dig through my posts - it's buried in my ramblings :P]
That being said, it depends on the skill of your doctor and what's wrong with you and the location of the problem.
My EP quoted his normal success rate was over 90%, but only gave me a 40% rate because he didn't think he could ablate all of my foci. He was really really good, he got rid of 99%, but then I started having PAC's the day of surgery and 3 months after surgery, my pvc's slowly returned. He said another area may have started and he will have to do another ablation so it doesn't affect my heart like before and I developed cardiomyopathy.
I had to have a pacemaker/icd implanted for malignant pvc's and my HR is crazy sometimes. I understand you about the range in HR; I've gone from 20 to being in vtach - vfib and my heart stopping; or it will stay in the 180's and my pm has to convert the rate. If you need a PM, it may help you greatly, and has helped alot of people.
For my ablation they gave me Versed, which makes you very very comfortable and feel nothing. I talked to the nurses and doctor during the procedure until they had to fully sedate me. The time of it varies on the location, how quickly they can trigger your problem and how easy the area is to get to; mine took about 4 1/2 hours - because my EP found the area on the first try.
Good luck and let us know what you decide to do.
I don't have any experience w. low heart rate but i do have experience w. ablations. The success rate w. them is super strong and it sound like you have bradycardia as i am sure your doc told you. The ablation itself is a really super simple procedure and if you are like the rest of us before you have it done you'll probably scare yourself and there is def. no reason to do that. Like i said on one of my earlier posts the ablation is a heck of alot easier than a root canal. If your doc tells you you'll be awake during the procedure don't panic...they give you specific drugs so that you won't remember a thing and trust me you won't...i had to really reach to even remember now 3 years after mine what happened during the following week. Most times you go home after the procedure and for me at 55 years old i went back to work like 2 or 3 days later. As for the other stuff you're going thru i'm in the dark on that one but i am sure someone will post soon to let you know what worked for them....good luck