I like the general idea but i think it would be better to add a "USE 30% EXP" button to the end of round screen so u can right then decide to use one on a better game or skip one on a bad game

Sailors under lvl25 get more than enough xp without bonus, to grow +1lvl/battle. So I can't use low lvl sailors if I don't want to waste my valuable bonus packs.

These xp packs are the best gifts that I've got from TNF, but sometimes it would be nice if I could turn them off.

Pretty sure this was already suggested before. 

Here.

http://fm.en.kupaisky.com/Community/Forum/View.aspx?num=20695&searchtype=1&pagecount=0&searchvalue=forcedplayer&sort=5&category=D02&page1=1

Welcome.