hey! So combat in this game is indeed intended to be quite gritty and loose with life at the early stages. But that’s also up to you as the GM to decide how it plays out. So if you feel like your adventurers are taking too much, just drop the enemy’s hp a tad. For Underguild I would certainly have them each roll up an extra character or two, and you can use “lost guild adventurers” who’ve been searching below just as they were, to fill the party back out.
as for the “modifier” on the bounties, yea it’s essentially the “theme” of the encounter.