isn't it wiser to let your characters get hit with the Lolth Curses and NOT remove them? There are 5 in the Encounter Deck, and that adds up to "only" 5 damage. Removing them costs 1 health, and if they get reshuffled that would make you take additional damage!
Each time you draw a Lolth curse every cursed hero takes 1 damage, not just the hero who drew the curse. So if you let them pile up on every hero, the final tally on damage will far exceed 5. Unless somehow its the same hero who draws those curses every time which is highly unlikely.
About reshuffling the encounter/monster cards. I wouldn't base any strategies around exhausting those decks. For monsters it would require a 25-30 tile dungeon, and for encounter cards its something like 45 black tiles/no explore turns by the heroes. I've played ALOT of sessions with all 3 of these board games and I've yet to see the encounter deck exhausted/reshuffled.