+Skill Level makes finding gear very stale and most uniques useless

If your item doesnt have +skill level, it’s worthless. It’s not as big of a deal in SSF but in Trade it makes finding valuable gear pretty lame, no skill level = quicksell.

The skill tree having much less effect on damage than gear is also a contributing factor

I would +1 on this.
Skill levels especially for spells are too big (~10% MORE damage per level and scale exponentially the higher the level goes) make gear without spell level (if it can roll them) drop drastically in value.
You can fix Weapon and Focus with essence (funny enough the focus can only roll +2 while the essence give it +3, make it the better option), but for other gear like Amulet, Helmet, Gloves it is no-go zone.
In addition to this, Mastery support gems / Dialla's Desire imo should not be a thing, it is currently straight DPS support which the game's original vision was very much against.

+1

The mod is too strong. It is just as oppressive in SSF as standard.

It should be competitive with our suffix mods, not completely out-class them.