Star Wars Stand Alone Films

They've still got almost a year till release. The big trick scheduling wise is building around the previous commitments of what is typically a very busy cast (Emilia Clarke with GoT commitments, Woody Harrelson works constantly, Donald Glover is like the most in demand dude in Hollywood right now). Six weeks of reshoots were built in, but if reports are true and the movie is as halfbaked as is being claimed they may need way more than that.

any word if the 3 remaining weeks was still principal photography or were they in to pick ups? (i imagine the latter)
but like you say, if there was significant stuff left to re-shoots that could be tough - though i imagine Disney contracts being very specific about how and when they can call you in and you essentially have to drop everything and go

i'm actually not too worried about any shift from comedy to genre action - any decent editor should be able to get footage and turn that into about 8 different movies - though the question will remain 'are there significant plot arcs not yet shot?'