Hi,
Live wallpapers can effect the performance of any device. I find some wallpapers can cause more delay on the touchscreen scrolling then others. I'll assume you have tried multiple wallpapers.
The next thing I would suggest is to try running the Phone Repair in PC Companion on your computer (backup your data first) then, without installing anything else, apply a live wallpaper (pre-installed on the phone) and test it out for an hour. Is it working better? Is there any hanging of the phone software?
If it continues, you might want to compare with another person locally to see how their phone is performing.
