Welcome bikegranny and congratulations for taking up the sport again. Well to borrow a saying from years gone by..."the proof is in the pudding." The best way to determine what hurts and what does not hurt is to go test ride several different styles of bikes. You will soon find out what kind of bike makes pedaling feel like a breeze to you.

I have a Specalized Sport Expedition and the angle of the seat tube is called slack meaning that it is considered less aggressive because it angles back putting the seat behind the pedaling just a tad. I found the bike far easier to pedal than my previous upright bike. I wouldn't have known that from looking but I felt it immediately when I rode it. I'm not a great hill climber no matter what kind of bike I ride so I can't comment on that. Also, I have knee problems and this style of bike does not make that problem worse. When I am at my worst with knee pain and have trouble with walking I can still ride.