With Cooldowns,
Disadvantage in PvE:
1) You can get GANGED easily.
2) Really annoying and hard to perform COMBOS.
Disadvantage in PvP:
1) Can get HUGGED by GangBangers EASILY. Which causes you to have NONSTOP deaths and NO KILLS.
2) Takes TOO LONG to finish a one on one battle.
3) Would make combos too annoying to PERFORM.
4) Would kill the challenge in ctf because of cooldown stopping players from killing other players before they reach the flag.

Nice Ones:
Pets
Suggested Ones:
Make a GUILD FUNCTION that allows guild COMPETITION.
Like add up all the numbers of kills from guild members= the guild kills number. Same goes with death.