So much to unpack here.
As a sucker for all things Alarith I would love to see a glow up for them. Getting rerolls back and maintaining the ignore rend -2 in Ymetrica would be super rad but is also pretty unlikely. I want them to keep the keyword abilities (alarith, vanari, hurakan) because they are fluffy and not op. Looking at it from the other side, I cannot see them removing shining company so those things should be safe.
What they should fix however are the stances on the stoneguard as you already pointed out. It always felt weird in the last two books so either change it so that it actually feels like stances(meaning only one can be active at a time) or simply take them out.
I am curious to see how they going to handle the MW issue. Maybe power of hysh goes from 1 MW on 5+ too 2 MW on 6+. Would make it more swingy and therefore less NPE. Don't know it really is a fine line to walk. Hopefully they come up with a good solution.
Dawnrider will probably stay as is because GW anticipates going into a horde season and this is where they could really shine.
As for new models, I hope it's not too much because I'm still way of on what I want in my collection.