My stoner friends were absolutely
livid when I went to the Netherlands and Belgium for a 2-week trip with my best friend and we never got high in Amsterdam
I kinda figured that there was always too much stuff to see and do to sit around and get high though, especially when I can do that back in California anyways.
It was the same with the hookers part of town in Amsterdam...it's weird and different and kinda cool, but just going to the beach back home, I can watch much finer girls without the same creepy vibe.
Getting back to the topic, I'd forgotten that taking your hand from a weapon is a free action. Still, I think it's a reasonable assumption that a DM might not allow a character to do so with Channel Spell, given that you're casting the spell simultaneously as you attack. Though 99% of DMs probably wouldn't really care whether or not a spell had a material component anyways =P
Unseen Seer/Runesmith doesn't sound half-bad to me depending on the group, though you'd lose another CL getting heavy armor proficiency.