What type of CBD-Base did you use? 3000mg in 30ml is 100mg/ml. With PG-based CBD 250mg/ml I couldn't get above 12mg/ml in a 30ml bottle before it turned white and the CBD isolate started re-crystalizing (50vg/50pg).

I uses isolate in 80/20 PG/VG. You will need a higher PG base as that will infuse into the CBD slightly better

There is extremely limited medical evidence for the "entourage effect," (edit: I couldn't find any peer reviewed studies after a 5 minute search) namely the idea terpenes have some additional effect when combined with CBD/CBG. Other people feel like that is a gimmick to sell expensive terpenes.

Adding CBG... will add CBG. It won't increase the CBD potency of course, but it will add CBG.

Without using THC, there's not much you can do in that regard. You could try using Delta 8 THC as that is the legal analog.