Hello insfca,
Welcome to BN!
In regards to your questions, I feel like self-experimentation is pretty much a given when it comes to NBE. I started off with NBE with very different goals than yours (wanting to get full breast development, suppress my masculine libido, etc.) and now 10+ years later I'm on HRT as a part of my MtF transition.
When I did start on NBE herbs:
*I ramped up my PM Ainterol to 3,000mg per day (at a later period, I would sometimes take 4,000mg per day, 3x a week)
*I never used PM Ainterol cream much, so I can't vouch for its effectiveness
*I never used RR. For an anti-androgen, I sometimes used spearmint (ranging from 400mg-800mg). I found spearmint to be very useful for suppressing my masculine libido.
For the duration of budding, I think 6 months would be a more practical timeframe. You can't speed up budding by taking more herbs (might have the opposite effect in fact!)
With the ideal cup size for hiding but also feeling your breasts, I think is a bit of a tricky question to answer. If you want to have a "flat as a board" chest, that might be problematic with any noticeable breast growth. However, it's not unusual for cis males to get some breast development (from diet, genetics, medication, etc.) even if they're not purposely trying to enlarge their breasts. Unless you're intentionally trying to show off your breasts, people might not pay much notice to your chest. The one exception to this is if you are going topless in public.
How do you feel about getting to the point where wearing a bra is necessary for your personal comfort/support?