is there a way to make testing as easy as on a Stamp?
If these chips had the limited capabilities of a stamp then maybe, but these chips are so much more advanced than the ones used on a stamp.

First, the 4550 has several ADC ports that need to be shut off when using them as digital.
Second, the configs will need to be setup properly.

You will need the data sheet.
You may also want to look at the internal OSC.