I am a member of house Redoran and want to kill Dren for some of the items in his house...Is it okay to do this (ie. will it screw-up the main quest at all if I do kill him?) Also, how long will the bodies/items on them stay in the world if I leave them there to come back for them later?

#1, Why do you gotta be a stooge and kill someone for items? There are better ways to go about it than that.

#2, Bodies don't last that long. But items left on the ground stick around forever, and I mean forever.

Solution? pick all the items you want off the bodies and snag em when you can.

which dren? they are many dren in the game.

anyway, just save your game first before killing somebody in case you migh goof up.

No, it won't screw up the mainquest. ;)