Hi Ed. Nice to see someone trying Abdul's base and recipes. To answer your questions, I always use tomato paste diluted 1 part paste to two parts water so i have to up the quantity a bit as Abdul does not dilute his and uses straight from the tin. This is captured somewhere in the BIR bandwagon thread I believe.
As for ginger / garlic, the recipe uses puree but making a paste of fresh would be fine IMO. It may give a slight difference to the outcome. Try both and see which you prefer

Are you using Abdul's basic gravy or is it his enhanced version. The basic recipe is good and more than comparable to most on here. His enhanced recipe is top line BIR though and worth the effort and very similar in technique to that shown in CBM's little india video.