Your machine is looking good. No problems that I can see so far.
I think that you will find that a Dremel tool shaft bearing flexes the plastic housing too much under heavy side loads and will cause chatter. Mine does when just using their router base attachments. Lots of people use the Dremels though. For fine detail work where small cutter bits are needed and speed isn't a factor the Dremel will work fine.
You can swap out the plastic bushings for bronze bushings, or you can modify the z axis assembly to install linear bearing blocks on the shafts. If the Porter Cable router is heavy enough to cause flexing in the y axis shafts near mid span, then something lighter like a trim router can be used.