Yeah, the additional leg would be the problem (only 9 seats available in these planes, would require some careful planning). Also some of the places aren't the kind of towns/cities that would have the typical crashpads...a lot of folks generally move in base, even if just temporary until the next bid period. As far as part time flying goes, I believe the company would like you to work full time for a year after attaining your ATP (or 6 months if you already have that when hired). PT pilots are typically based in HYA or BOS and have to be available 3 days per month (maybe someone else can chime in if I'm rusty with the PT requirements). I don't know a whole lot about the midwest routes, looking at the base awards for the winter those bases seem to be spread out as far as seniority goes.
I'm probably making it sound a little discouraging, but there have been people that commute, even with the 4/3 schedules, so it's entirely possible but as I'm sure you know it can be an adventure getting to work, especially with those multi-leg trips. I've only been with Cape since Nov but so far still loving the flying, it's a cool company to work for even if the base situation is a little different but if you could make it work it could be a lot of fun. Maybe some of the others out there have some different perspectives that might help.