Why do you give Normalize -1? Hitting Ground types, Volt Absorb users, Lightning Rod users and Motor Drive users with Thunderwave and Volt Switch and Sap Sipper users with Spore/Sleep Powder/Grasswhistle and Stun Spore can be a huge advantage.
It could still be exceptionally useful for a support set but anyway... taunt bait? I'd put it at 0 or 1, only reason it sucks is because delshatty.
Download is not a 4, i'd say 3 or 3.5. it's far too situational (porygon-z coming in? I shall switch to my SPECIAL WALL!)
Adaptability, on the other hand, i'd bump up to four. A double STAB boost was insane on something even as shitty as Crawdaunt with its base 55 spd. Can you imagine an adaptability tran? terrakion? Rotom-W? Hydrei?
Filter is a 3.5, as is solid rock. The mons that got it were all cursed with excessive frailty and/or dreadful 4x weaks, but if you have the bulk to take neutral hits, filter can be a godsend.
Forecast is... awkward to tier. Since it's only applicable to castform, you really can't even judge it on other mons, but in a vacuum i would definitely not say it's a 4. I'd call it a two or even one - with weather on your side but not your opponent's it could be a 4 but let's be honest that's like one in five or fewer battles, and in the others it's either a 0 or a -1 if you're sitting with a dead weight on your team when the weather switches.
Magnet pull isn't a five - 4.5 i'd say. It's what turned Magnezone into the dragon of FUKSkarm, but really it's still infinitely worse than the other trapping abilities (it's only good on maggy because it was already typed and statted excellently for steel rape – look at probopass for someone who wasn't thus gifted)
why the hell is multiscale at four. it's definitely a five. i don't even need to discuss this one
Prankster is a 4.5 or 5 - it's what made sableye OU viable, and what made Thundurus broken. Prankster is a godsend for anything with even a drop of useful in its movepool
I'd argue poison heal to be 4.5 as well - even though gliscor loses like all his support options (in bw1) by using poison heal > sand veil, it's totally worth it. Also what made Breloom OU in gen IV no doubt, it provides insane healing and status immunity.
Sheer Force i'd tier 3.5 as it's heavily movepool reliant - as examples of pokemon who don't give a shit it exists, conkeldurr (bw1, idk about 2) and Steelix.
Ditto (not the 'mon!) with Serene Grace
Storm drain is a four with all the water attacks flying (not the type!) around, ask gastrodon
idk about trace being a 3 - it's far too situational (porygon tracing Flash Fire tran? Cool! tracing DrizzleToed? Much less useful!)
unburden at 3.5 is far too high, as once it's activated, if you switch out, it becomes a zero. combine this with the fact that it's a three at BEST either way, and i'd feel comfortable tiering unburden at a 2 or even 1
Unaware i'd say is three-worthy. Setup sweepers are far less common in bw than in other metas, but they're still hard as hell to stop without perish song or unaware. (what bst 430 mon hard counters standard thundurus? QUAGGY DOES THAT'S WHAT)