I was told Rogue was really fun to play, and thought about respeccing my lvl 15 warrior. But then you mentioned the carry-capacity. Being the horder that I am, carrying almost 400 units of weight on my tank I wouldn't be able to respecc and still hoard. And now that I have above 50% crit chance on my 2-hand warrior and some good crit damage, I started liking her a lot more.
I've heard Rogue's are better in this game than the first, but not as strong as you for instance brought up Rangers, or Summoners. Do you have cloak/evasive maneuver, nether swap etc?
(edit: sorry just read your post again - you mentioned having to cloak) I'd imagine you'd want as many mobility skills as possible (tactical retreat, the scoundrel TP skill, phoenix dive etc) and then always aim to use a mobility skill to get out of line of sight of the enemies, at the end of your turn if cloak or feign death isn't up. I'd also advice getting armor healing spells (fortify, Heart of Steel, Bone Cage and the likes) and magic armor (Magic Shell and Soothing Cold) on all, or at least 3 characters.
Is his armor up to date with his level? Have you tried putting Stench on him, or Comeback Kid along with the Idol that revives you? Maybe some other characters can help burst down phys armor with necro skills or Tentacle Lash? (I like to go 2 phys dmg dealers and 2 magic damage dealers for a balanced party)
The scaling of gear goes off the charts, as you might be aware of ,thus getting new armor/weapons each level really helps,
This is about all advice I can give since I've yet to play a rogue. I do have an undead in my party though, and I noticed it's significantly easier to keep him alive if he's playing a caster or a ranger, than if he's a melee. Maybe you could cast Shackles of Pain + Living on the Edge for returning the damage to the enemies, and keeping him alive? I also recommend medusa head for petrification + crazy magic damage.
Good luck! Wish I could be more helpful -when /if I respec to Rogue I'll come back to you and do my best to give advice!
edit: Another tip is to give your casters bouncing shield for extra physical damage. Also enough warfare to get the knockdowns on your rogue. Maybe this is all really basic for you, but I hope some of it helped.
edit2: One more tip is just to embrace your rogue dying and turn it into damage. Give him "Unstable", combo that with Flaming Crescendo and Comeback Kid/Idol.
You can start out with Shackles of Pain (and maybe living on the edge) and then if he dies, at least he deals a shit ton of damage. Sorry for the wall of text mate!