I would think so on both counts as Magness does fine in the south and the northeast (showing good versatility) and will, in all probability, be compatible with Honeysweet.

Doesn't Magness take like 10 years to bear? & pollination is iffy as magness doesn't attract bees? Or perhaps I've had 1 too many glasses of wine?

Yes, it has that reputation. My Magness hasn't even flowered on Quince rootstock in 3 years. The other 2 I planted on quince, flowered in year #1 and #2. This summer I did a lot of branch bending, which will hopefully convince it to start.

On the plus side, it is a very pretty tree with nice clean-looking leaves, unlike my Honeysweet, which is right next to the Magness and covered with leaf spot.

Okay, any other suggestions for humid Iowa?

I'm not sure about what is best adapted in Iowa, but Harrow Sweet and Fondante de Moulins Lille are both very precocious. I'm harvesting Lille for the first time this year and the tree was productive (for it's size), with large tasty pears. The last couple have peaked in the 18-19 brix range. In fact, a Chinese co-worker who normally prefers Asian pears liked it better than all 5 types of Asian pears we tasted at the same time (I only grew 3 of them).

I know that it could be hard to find a Lille tree (Tierra Madre is the only place I've seen it). You could get a Magness tree (with its good disease resistance) and graft Lille onto it (mine has grown well and I can send some scionwood). That would also potentially help with pollination.