Forgive me if I am reluctant to start an account on the F2RP wiki page, so I'll just list what bugs/gameplay issues I've encountered here.
The Den:
# When leaving the Den Residential area, the camera always utomatically zooms to the original entrance to the Den West, not to the new entrance created for the Den Residential area. Furthermore, the game screen is covered black, but moving the mouse cursor "fills in" the game world. Moving the camera also removes the black area.
# A corner of the westernmost room of the squatter house in the Den Residential map is "off the map", which means that you can't see or interact with anything that's there...like a squatter fleeing from impending doom, for example. Not being able to kill all the squatters börks the new quest. This "hole" needs to be plugged somehow.
Gameplay issues:
Klamath:
# The Speech skill requirement needed to successfully confront the Dunton brothers about their cattle rustling is, in my opinion, set too high, especially since it's the only way to complete the quest. My suggestion is to either lower the Speech skill requirement, or come up with alternate skill/stat checks to allow the completion of the quest. (High IN and/or CH being an obvious candidate.)
The Den:
# Like above, trying to persuade the squatters to peacefully hand over the building to Mom is dependant upon the Speech skill being ludicrously high (80%+ minimum), considering how early in the game this quest is located. Resolving this quest peacefully should not be that hard, and more methods should be available. Resolving this quest optimally, however, should be tricky.
# When talking to the squatters, it is not really apparent that they will turn hostile if you fail to convince them to leave. I could try to reason with them multiple times without success, but they didn't turn hostile and "attack" me (read: Run for their lives) until I left the map and re-entered it. Suggestions: Either change the text to that it is crystal clear that they will attack you (and then make certain that they immediately turn hostile) or make them only turn hostile if you threaten them and fail.
I'll post more when/if I find it. Until then, happy Easter.