OK, Carl, let's take your points in order. 50+ hour weeks and no OT is standard for an SE, no matter what size the paper. I was in your shoes back in the day. And today my SE regularly puts in extra time. It goes with the turf when you're the boss.
The part-time position at the much larger paper would only be an option if you had health benefits from another source, like a spouse. Or if the paper had a history of promoting part-timers to full-time and promised you a shot at the next opening. However, some papers have two tracks, full-time and part-time, and never the twain shall meet. Caveat emptor.
Moving to a similar size paper. I wouldn't unless you would be SE and there is something about that makes it more than a lateral. Better gigs to cover, an extra week of vacation, bigger staff, better living conditions. Something that makes it better. Because all places have their warts.
Joining the circus? Unh-unh. Think Siegfried and Roy.