I had the same type of boots you are wearing until I finally got a pair to drop in Kz, so don't feel too bad about them :)
To address some points though:
1) are you sure you'd be losing a lot of stamina? Have you tried with different gems/enchants and such? I was looking at your gear compared to mine which is mostly Kara gear with the rest mostly Badge loot or crafted items, and you'd be gaining stamina from what I can see. Forgive me if I'm missing something though, it's 5:30 in the morning here and I'm about to toddle off to bed :P
2) I don't recommend looking to PvP gear at all! Exceptions being the spell damage mace and maybe (if you can afford to lose some avoidance) the shield. Get a spell damage weapon and that wit ha +40 spell enchant should cover you for OT in Kara unless your DPS is far outgearing you. But, generally speaking, PvP mace (or equivalent) with a +40 spell damage enchant is plenty for Kara. Remember that PvP gear does not give needed avoidance stats, so they largely fail for use as tanking gear.
3) Don't roll just for the sake of having epics. Just because you have a blue and you see an epic drop doesn't automatically mean it's better. That said, if the piece is an upgrade or will be as soon as you gem/enchant it, then you have every right and reason to roll.
For you, yes a lot of what drops in Kara will be an upgrade. Save up your Badges though to get Chestguard of the Stoic Guardian and Libram of Repentance. Those will be the biggest pieces of Badge loot for you right now. And, if you see a King's Defender drop, don't take it over a Warrior :P Better yet, just don't take it. It's worth more to a Paladin as a Void Crystal (unless you are still wielding your current weapon when you see it drop, but make your life better, and don't be using it :D spell damage weapon all the way).