!!!MAY CONTAIN SPOILERS!!!
Suggestion #1: Cosmetic Armor
Please bring back the cosmetic armor option we all enjoyed in Odyssey.
Suggestion #2: Rune Pouch
It would be really nice to have a special pouch just for runes so they don't take up half of my inventory screen. Too cluttered currently.
Suggestion #3: Romance Options
The current options are just way too limited. We need more, both male & female. Personally, I would love to see Augusta the Cheerful become a long-term option.
Suggestion #4: Marriage Option
Eivor should have the option to get "married" to their long term partner after a cute (optional) side quest. Perhaps it could start by one of the settlement NPCs commenting on Eivor's relationship, which then gives you a prompt to respond something like "yes, we intend to marry" or "we don't need to marry to show our feelings (no)". If yes, then you start a short side quest that involves proposing, inviting allies, & enjoying a wedding feast.
Suggestion #5: More Realistic Horses
Seriously, the current horses suck. You can do better, Ubisoft.
Suggestion #6: Permanent Reindeer Mount
I loved the reindeer mount during the Asguard quest line. It would be really cool if we could have a permanent one.