hunter talent optimitzation

Hi, quick question about hunter talents:

Imagine the typical talent build with 3/3 points in [Focused Aim], you have 5% hit from gear and 3% from talents, ok. Now if there is a shaman in your raid/party group this means u have draenei and means 1% hit extra. Does this mean you can go for only 2/3 point on [Focused Aim] and still have the same hit chance for your ranged attacks? Because i see all high gs lategame hunters using 3/3 anyway.

Bonus question: if there is a blood dk with [Abomination's Might] or other hunter with [Trueshot Aura], can i spend my point from [Trueshot Aura] in other useful things right?

They use it because they wont rely on random stuff. Some "theoretical" dps increase that my or may not be there sometime maybe kind of is just not worth the hussle, problems, wasted time, annoying everyone with their crap, etc.

I guess if you go into flow state and presence of mind in every encounter, use every ability and every milisecond of the encounter at max potential, sure such things will give you few crumbs. At that point your guild will put up with pretty much anything you do, as you are one of 0.01% of top of the playerbase. Also then you will know how useless it actually is and will not care to "optimize".