You don't really go into any detail on the straight cuts, but it occurs to me that I should have probably mentioned that the tablesaw (as well as the bandsaw mentioned above) are also well suited to cutting plastics. Most any tablesaw blade will do the job for straight full-depth cuts, but for partial depth cuts you'll need a flat top grind or dado blade if you want flat bottoms.
Still, the router is one of my more favored tools for milling plastics as it is just too easy, though it does help to wear long sleeves so that you are not startled by the hot plastic striking you. It won't burn you but it can be uncomfortable, especially if you are not expecting it. The router tends to yield very crisp edges with little if any cleanup work unless you want optically polished edges.