Keep in mind, it's nearly or completely impossible to kill a smart player with a trap. For all of these, note that chorus fruit could be used to escape before death (and ender pearls for less effective traps). Also note that people could eat gapples before teleporting to the trapper. If the regeneration heals them faster than the damage they receive, they could just teleport away once they realize it's a trap.

Additionally, all these creative ideas about combining lava with potions and attacking, etc., won't work as effectively as planned: While a player is flashing red from taking damage, they can't be damaged unless they receive more damage than the damage they just received. With lava, potions, and attacking, most of the time the player will only receive the lava damage. Milk buckets could be used to cure poison otherwise.

Do staff choose cheats to casually catch careless cheaters?

I must confess, that cunning alliteration may have been a bit confusing. In all seriosity though, do staff use hacks themselves in order to catch hackers?

I have two pretty similar questions:

1. Do you get your rewards when you log back on the server if you vote while off the server?
2. Does your vote counter still increase if you vote while off the server?