Fine, I'll answer.
I have done 2 grams of test a week on a diet and experienced absolutely no water retention, so yes water retention is very much carb related. As long as you keep your estrogen in check with an AI you should do fine. As for using VAR, you probably won't be able to tell the difference if you are using it or not with that much test. There may be some benifit to the joints and tendons however.
As for suspension, I have never used it. So I can't tell you anything about that, but I would suspect you should not have any problems at all. If you do use test susp. try to split your injections into two per day To keep your levels high, inject in the AM and later, maybe after your workout. It is pretty smooth stuff, so you should be able to use a slin pin.