The Tavern

When i run into a tough opponent i should probably just skip the floor for now. But i am worried that monsters will pick up items, or a jelly will destroy them. Is it smart for me to stick around and avoiding the monster while getting more items, or should i just skip the floor?

most of the time you will be safe just skipping the floor and returning later. if there is something you see that you don't want to leave behind drop down to the next floor and come up another set of stairs so the baddie has time to meander away

You can also use the annotate function pressing '!' Also Map (X) plus e(xclusions) may help, especially in combination with autoexplore.
X and [/] cycling trough Floors is usefull too to find your foes.