I do not think you can run a SRAM AXS road cassette (i.e. 10-36 or 10-30) with the MTB rear derailleur.
​The 10-50 cassette will still give you the same top-end on the road, it just comes with bigger gear jumps and more of a weight penalty.

For 32mm road tires, my favorite are Conti GP5000 TL's. Rene Herse Stampede also looks like an excellent choice. Either would be fine keeping up with the fastest of road groups.