Aspirin can definitely lower risk of clots, and about the donating blood - I see a lot of ppl sayin' once every 3 months or so - that s a recommendation for a non-juicer. If you use a lot of gear - wont hurt doing it more often. I ve heard bbers doing it every month at different stations or just draining at home.
Hematocrit is a pain in the butt - some ppl get high levels from HRT, other can barely got affected from high doses
Problem with that is it can really lower your iron levels.