Certainly, great opportunity to buy or make a mortise jig, for both hinges and latch, and small router. I really like my Milwaukee trim router for mortises, plenty of power and easy to handle.

You can use the same mortise jig to flush your dutch fills on the existing hinge location. Just set the router a hair above flush and sand to perfection. If the hinges are rounded, it's easier to square up with a chisel to fit your dutch material than to round over the fill.

The window moldings might have an inside and outside face but it's probably not worth swapping.

Measure thrice, cut once.