PIC32 receives/transmits improper data on serial port
For all questions  regarding timing, I recommend starting with something dirt simple that confirms all the system clock configurations.  Flashing an LED at a known rate is one way to do this.

Clock setup can be tricky, and step 1 is to make sure you got it right.  Even if you get your clock config all screwed up, PICs tend to find a mode to start up in.  I start pretty much every project making sure I have the clock right.