Yes, but you won't be able to buy/sell/talk with the store/armor and such npcs if you have more luxon then kurzick faction, or if you have zero in both
As far as getting res'd in wierd places, the Kurzick rez shrines can be used, if you have a higher amount of kurzick faction than luxon, OR if you kill off the Kurzicks guarding it, just talk to the priest and you'll find a way to kill them
your allegiance as a guild has nothing to do with your pve experience. It is the amount of faction for both sides that YOU have that will decide which side will favour you and which side will refuse to help you.
