First of all, I don't think you have to be a "highly intelligent" person to be a professional Blackjack Player (I'm not, although I was always good at maths). An above average intelligence will do. "Above average to realize the potential money making business this is (none of my friends or there friends can understand how I can be a professional gambler, that's why I hate the word "gambler". To be a gambler means to "bet against the odds". I don't, I bet with the odds!) And an average intelligence to implement the advantage play methods. It might all seem hard to do, all it takes is hard work and persistence. I play Hi-Opt II as my count and I also doing some ace tracking which is very effective. Most wannabe advantage players think it's all too much. Well, to a recreational player this is true, but if you play to get as much money as possible, then you must use all the ammo you can get you hands on, and for me this is the most effective strategy for me. Note, that I said best strategy for "me". Everybody is different, and some systems work better for some than others.
As regard to bankroll, that really depends on what limits you prefer playing at. Most people assume that you must play at $25 min to make good money, this simply is not true. You can make good money playing at $5 min tables. Plus at the $5 min you would get substantially less heat than some playing at $25 min. It also depends on what kind of a risk vs reward you like. I personally like playing with no more than 5% Risk Of Ruin. Many other players prefer less risk, and that is fine to. In fact if I was JUST playing BJ, I probably would also want that, but that's another advantage of playing other games professionally.
Another factor is spread. the general conception is to play 1-12 for 6 decks (my favoured game), I at the moment I play 1-40, but that also depends on casino, country and past experiences. You should spread with whatever you can get away with. I believe that if you are going to spread from 1-12, that will cause as much heat as going 1-40. There are many different views, but that's good because it keeps people thinking and coming up with new ideas, there is no right or wrong way to play BJ(except progressions!). For me my Blackjack bankroll is just over 100 max bets (4.25% RoR). For someone to play just BJ as a pro, I would suggest, as many do at about 200 max bets (0.5% RoR).
I would say that the biggest and best advantage of being at pro gambler as that you can organize you own day to suit you. Most tournaments are in the evening and BJ is mostly 24 hrs (umm..those 11 am alarm calls!!). I can imagine it being a very big step to quit you job and play pro, I started when I as 17, so I never really had a "real" job as such, and as I think Rob said it also depends on want responsibilities you have, wife, kids etc.. and also persuading them that this really is possible (in fact that never happens!)
I think I have pretty much covered the most common things (I was in one of those moods to write a long letter!)
(Hi "Learning to Count", Thank you for welcoming me).
good tracking
TRACKER.