For non-moon druids it was more or less a ribbon ability anyway... so...
Actually, as a person who played a Dream Druid, I disagree. Wildshape had massive utility outside of combat, and since it was an action to transform, it was rarely used in combat. It had two major points though.
1) Becoming tiny to scout was AMAZING. It gave the Druid a lot of flexibility and fun, flavorful things they could do. I particularly enjoyed becoming a spider to fit through cracks and sneak ahead, or becoming a giant snake to move through the swamp. I once became a Jaguar to hunt a scent as well.
2) You could (at a point) become Large, and that had some limited utility as well. I had a player who became a horse and was able to carry an unconcious party member.
Now? The Large utility still exists, but the major use I had for Wildshape is gone. You can still bloodhound with it, but you can't use it to scout ahead. The smallest you can be is small, which is a normal dog size or a baboon. Looking at the MM list? Most animals were tiny, cats, badgers, snakes, hawks, lizards. By moving tiny to 11th and cutting it down to 10 minutes, they've gutted the biggest and most common use for the ability.
edit: I am speaking as DM here and a bystanding player: being able to transform and have so many extra hp felt imbalanced. That everyone compares them to the barbarian is in my opinion rather proving my point, not theirs. It is too much.
5THP per level for a moon druid seems quite appropriate. I'd even say WIS bonus + 4THP for everyone, WIS bonus +6 THP for moon druids. Of course youbare knocked out of wildshape when your THP are lost.
A little boost at level 1 and 2, because 5 hp feels a bit too low at level 1 for me.
I'd also add WIS bonus to concentration saves. I really hate melee characters woth concentration spells not being able to hold them 40% of the time.
The problem for me is that we keep trying to make it a combat ability. It is for Moon druids, but for every single other type of Druid, Wildshape was not a good combat move. Because of the Action economy. But now? Now they are forcing it to be a combat tool, because of the level 5 multi-attack. But they are still making it an action.
And that will never work. Just look at the Devotion Paladin, they changed the blessed weapon channel divinity because no one used an action at the start of combat to activate it. Rage would be terrible if it took an action to activate. Ect Ect ECt.
Additionally, my Dream Druid did end up fighthing in Giant Snake form... and I really found myself wishing the enemy would go ahead and knock me out of it so I could be more effective. I'd gone from 18 AC to 12 AC, from dealing 13 damage at-will to 5 damage at-will, from a +7 to hit, to a +4 to hit. In every conceivable way, it was worse than just being myself. But I didn't want to waste the wildshape until it was used up, because hey, 13 extra hp was decent. But the enemy didn't even bother attacking me, because I wasn't enough of a threat to warrant attacking.
Treating Wildshape like a combat option is, I think, a mistake. Unless you are willing to make the Moon Druid's bonus action shift universal.
Also, side note, your suggesting for Temp HP MAXES at 9, and knocks them out of the shape when they lose it? You do realize that if you want a 12th level Druid to use wildshape in combat, you are asking them to use their action to gain 9 temp hp, lose their AC, and then basically immediately lose the form when they get hit because NOTHING at that level is going to hit them for less than 9 damage. It is an utter waste of time,
