Trek Belleville. The dropped top tube means better standover. On the large frame, standover is 31.6" with top tube of 60.5 cm, while the medium has a standover of 30.1 and top tube 59. Sounds like it meet your sizing needs at least. The geometry is also a lot less aggressive, with the porteur style bars, so it meets all three of your "musts."

It also hits #4 and #5 on your "wants." Comes with big tires on 700c wheels and has a steel frame (though it is heavy for it).
No way to do disc brakes or cantis, but I suspect you could still do pretty well with a set of kool-stop salmon pads.

You'll likely want to do some switching out and upgrading, but the beauty of this bike is that it's cheap ($600ish) and versatile. If you want, you can throw on a derailleur system, replace the front rack with low-riders and go off on a tour. If you want to go crazy, you could replace the fork, stem and bars—this way you could have drops plus a disc brake in front (which is all you really need).

Seems like a good fit to me.