Thinking of naming baby girl [name_u]Brooke[/name_u] but not sure if its friendly enough. Are [name_m]Brookie[/name_m], Brookey or Brookedy totally ridiculous options for formal name, because this is what she is tending to be called? Or do I just use them as nicknames or find a cute middle?
Yes, ridiculous. Sorry! [name_u]Brooke[/name_u] is perfect as a formal name. The “friendliness” that you want can easily come from her nicknames. 
Yes. [name_u]Brooke[/name_u] is perfectly fine by itself.
[name_u]Brooke[/name_u] is definitely nicer by itself. The other names are kind of [name_m]OTT[/name_m] to me.
I prefer just [name_u]Brooke[/name_u].
[name_u]Brooke[/name_u] isn’t my style. I just fine the sound of the name very harsh and abrupt. It’s not a “friendly” name in my opinion but it’s preferable to [name_u]Brooklyn[/name_u] and the other names you mentioned in your post. You could give her the nn Rook or Rookie if you like them better.