Hey, don't worry about the questions. You ask all the questions you need to. That's what this forum is all about, helping each other out.
I know some people use an 11.1v batt with the stock set up, and never have problems. But, I understand you risk burning up your 4 in 1, and if you do that, you might as well buy another heli because the 4 in 1 is more than half the cost of a whole new heli.
This is just my thoughts and my opinion about modding. Some mods are good, some not so good. A lot of the time one mod will only lead to the need for another. But if you enjoy that kind of thing, then that is what you should do.
My opinion is to use the HBFP mostly as is and treat it as a great trainer. (a set of Super Skids would be a nice addition) As soon as you can fly it comfortably, then move up to a CP heli like the Belt CP or EXI 450, or better yet, go ahead and get an E-Smart 600.
But again, that is just MY opinion. There are a lot of people that have other thoughts and they are just as right as mine.
Maybe some of the other guys will chime in here and give you their thoughts.
By the way, I'm glad that you are so excited. Great hobby, ain't it?
Donnie D