#1
I was thinking of the idea for a future rig (i can't really afford it right now but my current rig is solid) and using a tube power amp, possibly the fryette ones (Kerry King swears by the kt88 power tubes in his marshalls), to drive my speaker cab and using a multi-fx (i'm liking the boss gt-10 we're using at church) for the preamps and tones. i love the customizability and versatility of multi-fx, but would the tube power amp keep alot of that "warmth" that tubes are known for?

i'm sure this isn't a new concept; Dino Cazarez used a mesa power amp with a line 6 pod rackmount in Fear Factory.
Dream rig:
Marshall JCM900 Amp
Avatar Custom Cab
Boss Fender 65 dlx reverb pedal
Noise gate
MXR EQ
Boss Dynamic wah
Boss Harmonist
Ibanez Echo/delay
Dean Custom 350
Dean XMNT V-shape
#2
Pretty much everyone who uses a higher end preamp does this, digital or not. If you like the tones from your GT-10, it works.
/rig