How to preserve lineart with a crappy tablet?

[Shachza]

So I've got a crappy tablet.  Like really crappy.  Like "for some reason pressure sensitivity doesn't work at all in Photoshop" crappy.  It's a Genius MousePen 8x6 that was gifted to me in lieu of the Intuos I asked for.  I updated the driver from the Genius website yesterday, and in the tablet options from the system tray the pressure sensitivity works.  Just not in Photoshop.

So two questions that would help me:
Does anyone know of anything else I can try to get the pressure sensing function to work in Photoshop?

Or

Does anyone know an easier way to clean up smudgy pencil linework short of erasing everything but the lines?

Here's the artwork in question btw.  Warning, there are ponies ahead.
http://shachza.deviantart.com/#/d5bkkp8



P.S.  If anyone would like to donate a couple hundred dollars, I could just get an actual tablet...