PrinceZane-
First off, dude, if these guys are your RL friends, I would seriously try to tone down the "stupid" comments. Admittedly, their attention to detail and tactics need work, but that might just be more reflective of their playstyle than intelligence. Somehow, just saying, "your tactics could use some improvement- here are a few suggestions" might go farther than, "boy, that was a stupid move."
OOC, I would try helping out with tactical 'cheat-sheets' for each character, with the main methods they should use. This does not have to be anything lengthy or fancy- just a quick bulletpoint list of methods for different situations might do wonders, as quick reminders to the players in-game. For example, the fighter's sheet might say something like, "mobile skirmisher- use terrain and cover" if he is a dexterity-based PC, or "melee tank- take out enemy mooks with great cleave feat".
IC, perhaps your (presumably high-INT) rogue could become the tactical leader of the group. Think of Cyclops keeping Wolverine in line for the benefit of the team. That is not metagaming, but rather effective tactics of a different sort. Instead of trying to fight undead as a rogue (a sub-optimal tactic.. LOL) you could be the team strategist, sort of a field commander dude. I also like the earlier idea of using a wand of CLW as an offensive weapon against the undead.
