As mentioned elsewhere I 'volunteered' to write something we can point poster to when then have yet another problem with baud rates and the like. It's still work in progress and will get finalised over the next couple of days.
#3 How have you proved that your chip is running at xxMHz?
#4 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand." - Heater's ex-boss