PS4!

Yes to pretty much all of that, that kind of thing seems perfectly fine. The "valid explanation" thing was only for the elf part so if that's not there you don't need to worry about it.

As for the character growth, that mostly depends on how the character starts out and what you intend. If you want them to grow a lot, by all means do so, but if you want them to be decently powerful at the start but not overpowered you don't have to. In that regard t's your choice.