You have basically the same deal as me... no blisters (well mine have been repaired before, and I have found 1 since)...
But basically if it had anti-fouling on it already at one point, then it likely has has barrier coat as well.
Scrape off all the anti-fouling (only if it's so bad that it's flaking off)... If you do this... do it all. Sand, 60 grit or 80 grit. Once smooth... use a wash to remove any mold release if you accidentally hit fiberglass removing the anti-fouling (trust me you will, lots).
Once that is done, fill the scratches, and gouges (there will be plenty)... fair the keel (make everything smooth-ish)... Then barrier coat. Then bottom paint.
The alternative (that I now STRONGLY recommend)... soda blast the bottom. Its quicker, and less labor for you! Even if you've never done it, the learning curve HAS to be better.
This is what I started with:
I've since VC17m'd the bottom (I'm freshwater).
But anyway, I have to say the Interlux 2000e Barrier coat is neat stuff. Hard as nails, auto-levels nicely, and is very thick/tough. Also I used interlux water tight for fairing (boy that stuff is a pain to sand).
EVERYTHING is toxic! Copper ablative, epoxy paints, bottom paints, sanding is especially bad. Use a lead paint removal (or better) respirator, and a bunny suit, gloves... the dust gets into everything!