[MangaD]

There's gonna be a 3 month period.

Nope. Too long, people will definitely forget it. 3 days is more than enough for a Single Player contest, since everyone can choose the best time for them to play/record within those 3 days. There is no time zone conflict nor network problems (except for uploading the video). Also, it will be our first Contest here, let's keep it simple. ;)

-At the 2nd month there's gonna be 2 person elimination tournament where you can use an op, only if both teams use one op char, or 2 op chars for each team...

Double-elimination tournaments means each competitor can lose one fight without getting eliminated. They are eliminated from the tournament upon the second loss. There are no teams here.

It takes ages to level up a character and that totally boring to do that again n again...

As I said, there are tricks to level up fast.
https://www.youtube.com/watch?v=wY4A59pO_ps