Combat is turn-based and there is no time limit on each round in a PVE Pet Battle. You can take your time to determine which spell to use next. Some pet abilities have multiple round cooldowns, while others can do extra damage if certain conditions are met. Be creative and have fun testing which combination of attacks works best against different wild pets!
Apparently a lot of the current World of Warcraft Classic closed beta testers are reporting things as bug that, well, simply aren't. There are enough of them, in fact, that Kalvax, the Classic community manager, posted a lengthy "Not a Bug" list on the forums. Some of the things that are actual features in the game include Tauren melee reach and hitboxes are larger than other races, Warrior health regen is working as intended and creature respawn rates are "much slower".
An advice for those who are trying to compete monopolizers: you cannot beat them by selling for less if they follow right steps. You should do opposite: sell for more. Because market will come down if the price goes unreasonably high. You can set a bid on item for the price it should cost and buy out price for higher than a monopolizer is selling. So, common buyer may get an item for the right price or monopolizer has to buy the item at his loss.