3. As a defender/guardian, you are not allowed to use any untouchable skill you have ( e.g. DF,POG or UT).
You should also disallow the other classes skills which are equivalent to POG (Santuary) and UT (Unbreakable), also SG (Impenetrable Guard).
The warrior equivalents:
PoG - Hard Lord
UT - Berserker
SG - Frenzied Force (I think).
It is only fair that these skills (and other class equivalents) are disallowed too. You also didn't specify, is it party buffs or self buffs only i.e. can a warrior get Prayer and Etain Blessing before a fight?
The rules don't seem to be very thought out, it also seems a little unfair that only 1st place gets a prize, surely second and even third should get a conselation prize. 2 OP entry fee leaves a 32 OP prize pool, this could be split into: 1st = 18 OP, 2nd = 9 OP, 3rd = 5 OP, otherwise it doesn't give much appeal to someone who may want to enter but know they can't beat someone that's already entered.
3rd place would be 2 losers from the semis fighting for 3rd and 4th.