I don't like having to go over something like this, as this is in no way a priority in this state of the game; however your suggestions are somewhat weird, in a tournament environment you'd probably follow the already set rules over many years of competitive play.
This means no item uses besides held items by the pokemon at.
The max level is obviously 100, nobody would want to compete with anything below, and you can't pass that level, so there shouldn't be any problem here.
A timer is ofcourse a necessity, and a spectator mode. The only real question regarding pvp cannot be answered until it's been decided how to handle legendaries, the question of banning some pokemon, or splitting up tiers (Uber, OU, UU, NU), which is also problematic, seeing as this is third gen, and the current gen being used to play competitively is fifth gen, meaning information would be scarce. Some people also hate "tourneyuguu", however if you don't follow rules set by people with knowledge on the subject, they'll simply use the holes they fix against you, fighting teams consisting of nothing but legendaries would get a bit boring in the end.
