Assuming just taking Rex on and ocassionally Prime you should be fine, trips are shorter but an SGS can help extend that. I'd also recommend baskets of strawberries for that 25hp heal, you can use brews if you want but that's up to you. Good thing about DKS is it's lots of little hits not one big hit like tanking at Zamorak.
Zamorak - You can't tank this, you'll get absolutely destroyed. If you have someone else tank then you'll be okay, but still...You might want to trio.
Saradomin - If you take Stamina's this boss isn't actually that bad, you can solo her (although not for too long) and if you go a duo you'll do fine as well. Just a slightly shorter trip.
Bandos - Don't take, you'll be fine. Just pray range and take a d hide top. All you really have to worry about then is the melee'er. I'd also suggest bringing fighter hat and warrior ring (i) for that boss, especially if you're 60 attack. it just helps you deal more damage to the boss and is going to help your tank out so much more.
Armadyl - I don't know how well you can/can't do the chin method here as a zerker, I know the Rcbow method B0aty on his one man army killed 1 a trip which is...Tragic. This will be a struggle but I'm guessing at least a trio here, yeah it sucks but what can you do.
Corporal Beast - I don't see the point working your ass off on this boss to get nothing useful.
Kalphite Queen - Yeah this boss is do-able as a zerk, only major difference is you'll get hit harder and can't abuse Verac barrows set.
Vet'ion - Get Rekt
Castillo - Get Shrekt
Venenatis - Abuse range method, should be fine. A partner is preffered I'd say, I don't like to solo this boss as a maxed main. Especially with the amount of pkers that come at you.
Chaos Fanatic/Crazy Archaeologist/Scorpia - Ez, you'll smash 'em
Chaos Elemental - Safe spot via tree, emerald bolt (e) and flinch him
Zulrah - Plenty of topics here on how to deal with her :)