starship trooper

So I play in a band once every week. I am completely convinced that our live sound sounds like garbage. In particular, my guitar sounds way too thin/bright. No matter what, it always sounds like that in the venue we play at.

Unfortunately, I'm a complete noob when it comes to live sound. I have never even miced by amp before, so I guess that's where my thin tone comes from. (We only mic the vocals, but we have enough mics for my amp; it's just too inconvenient to mic everything.)

I can tell our mix isn't very good because, well, the more musically inclined audience members have complained about it.

Some questions:

1) Would micing up my amp and therefore getting access to a mixer allow me to beef up my sound/tame the highs? Silly question, but I feel like it's a lot harder than I think it is.

2) I'm planning on quitting this band eventually, and forming one more suited to my style of music - prog rock. At one point, in the band King Crimson, as I'm sure many of you know, there were two guitarists, two bass/stick players, and two drummers - the "double trio" that made up the band. I want to start a band based on that concept. How difficult would it be to pull off a great mix live?

Thanks for reading,

starship trooper