HU rake vs 6max/FR rake

[Sheetah]

Tonight's match was a good reminder of how brutal rake at low stakes can be. I was sitting fully armed (NL50 cash) when an opponent joined and put ~$20 on the table. As it usually goes he won something for me, I was insta reloading and game turned into vbet/suckout roller coaster - him greedy to get more, more - me determined to get it back plus the rest. What I'm trying to say that untypically long match had decent amount of untypically big pots. Eventually I won, closed the table after he left, took a look at BR amount and shockingly realized I was back exactly where I started. Rake completely ate my fish! [img]/images/graemlins/frown.gif[/img] Almost hour of playing for nothing.

Some questions:

Back in old days I remember looking at my PT stats - amount won was very close to rake payed, ex. $100 won - $95 payed in rake, won/rake ratio was always close to 1:1 ...
Q1) What's the won/rake ratio at HU cash after some decent sample size?

(closely connected to Q1) Say you have a rakeback, ex. 30% ...
Q2) How much RB will increase your overall profit?

Since HU standard deviation is typically 2.5 times larger than 6max RB, it's logically to assume HU players are raked more ...
Q3) If I have a bonus to clear, how faster will it release compared to 6max

I'm just trying to get the idea of where the percentages are. No need for hardcore math, just pull a random number you think is close enough and I'll be happy.