1) Agree with Carpone about the 8th Druid level for Vorpal Wolf - looks interesting though, to the point that I'm about to log onto lamma to see if I customize it to my own satisfaction.
2) Melee Arti / Barb could be okay. Dwarven waraxe + Glancing Blows from rune arm in off-hand + Con to damage isn't the worst idea I've ever heard, but I don't really get what it IS. Dps sounds like it would be mediocre, no incorporeal or castable displacement or particularly much dodge and being limited to Medium armour I query it's use as a tank. Self-healing will also be limited to scrolls while not-raging, which sounds okay, but difficult in practice. I don't know.
I could be convinced, but suspect you'd need to be very good at this game to make that character fun and effective.
3) Ice King amuses me. I 'get' the sorc 3 cold savant thing; it's an interesting thought and there's some nice stuff there... but I don't know. Not for me, but someone might get a lot of enjoyment out of it.
4) Quarterstaff build, no idea. Until I pull a Sireth I'm not going to think about them.
5) I loathe the arti/mechanic build. I have no idea what 6 rogue is bringing to that party apart from Int to-hit. Since you probably want Combat Archery anyway, or at least Improved Precise Shot, Dex to-hit is absolutely fine.
I see these on live and in these forums often and it just saddens me. It's a really dumb split.
2 Rogue for Evasion I faintly maybe understand since you don't want to loose the level of skills that 2 Monk would give you, but to me it's still insane.
Summary: Rogue/Artificer provide almost 0 synergy to each other in any department and the 6 rogue splash gimps the character immeasurably beyond what pure rogue or pure arti or 18/2 arti give.
Genuinely interesting builds though. I'm taking Vorpal Wolf and 3 sorc splashes away as concepts I hadn't considered at all.