I've grown fond of mixtes in my old age. It's not really a step through frame, not without some body english, although I think that was the original intent. Not "easy" but "easier" I guess. There were a couple of Japanese versions that came with halfway decent tubing. So they are light-ish sort of and have a ride that's both sporty and super comfy once you set em up how you like. I scored an old Nishiki for about $50 and shoulda never sold it, that was a great bike. Have my eye out for a Centurion. Currently riding a new Soma Buena Vista, which is a beast of a bike. A lot of the big names imported them (Peugeot, which was the first I believe; Raleigh made some pretty ones) but I generally prefer Japanese steel to keep the weight down to something manageable.

Reach on those things tends to be a smidge longer than road bikes of the era so I would suggest losing the drops, get a short stem and even consider going down a size from what you're used to. I have not had to resort to cruiser bars yet, I found moustache bars and similar (eg Soma Sparrow) to work for me. But you can put North Road bars on em if that's your fancy.

I was never an athlete and I dang sure ain't one now, but I like having a nice bike and I kind of get that feeling from a good mixte a little bit. Not a racer by any means but not a dog either, not if you buy a nice one. Something about that Nishiki really worked, I could ride the thing all day, felt effortless but still surprisingly nimble. Cool bike. OK well "cool" is a strong word. But definitely a bike.