First off at the moment this title is a complete mess.......
re: resolution, there seems some hardcoded reson that only certain resolutions are available probably to do with the way it renders in 720p,900p or 1080p
try finding C:\Users\*YOUR USER NAME*\Documents\My Games\Dead Rising 3\rendersettings.ini
there is an option to add your own resolution but i believe it will still display it in one of the resolutions in your options, maybe it scales it i dunno anyway......
look for this section // Render Settings
Language = en
ScreenWidth = 1920
ScreenHeight = 1080
this is also the file to change it to run in a window if you want to try that out.
I notice you say "it only lets me pick from 1920 x 1080 or 1620 x 1050. i wanna play at 1920 x 1080p"
if you have 1920x1080 selected.... whats the problem?
Ive been plagued with randomn crashes with this game and the only way it seems to run 'properly' is for me to roll back gfx drivers to nvidia 335.23
you can uncap the 30fps limit by adding a 'user.ini' notepad doc to the game installation folder, where the exe is, and adding gmpcr_unlock_frame_rate=true
in the user.ini
But to be honest the fragile state this title is in makes me keep it at 30fps at the moment, and therefore keep the refresh rate to 30 too.
The only other thing i can suggest is if you run fraps, msi afterburner, hwinfo64 etc close them before running dead rising 3 if your experiencing any crashes or problems.
Unfortunately by the time they fix this truly unoptimized pile of poop, people will have gotten tired of it and moved onto something new.
hope ive helped in at least some small way, and good luck.