Steve,
I've used the Dremel router for cutting in the hollows, in foam wings, for retract gear in R/C pattern ships. Same for the gear blocks.
For what you need to cut, my guess is, a simple jig saw will be fine.
I cut all the pieces for The LOSER with a band saw, Dremel table saw and a jig saw. Check out the build Thread. No place did I use the Dremel router. I do use it to cut wire for gear.
Unfortunately I don't have an electric sander so I spend a bit of time getting as close as I can on the line. I do have to sand.
What are you scratch building?
Charles