Doubling means making a copy of the track and panning it in the other direction. So if one guitar is panned to the 3:00 then pan the copy to the 9:00 or 10:00 or wider if you like. This will do ALOT to make your mix sound bigger and have alot more presence. I almost always double guitars, vocals, strings, and whatever else I want to give me the density Im after.
As far as compressing the vocals, Im a fan of dynamics myself (especially on vocals and drums) but Im also a fan of fullness and brightness and not having vocals drop out a couple of seconds here or there. In a live performance the singer is moving around and is not always 6 -12 inches in front of the mic as he/she would be in the studio, and the vocals move in and out. Compressing them will smoothen that out somewhat and keep the levels more consistent. Im not saying compress it like a guitar, Im talking about some easy 2:1 ratios with a 6 ms attack, maybe .5 sec release. Maybe 3:1, maybe 4:1. See what sounds best.
You got some very well tracked material there. The mixing shouldnt be too involved.
Just out of curiosity, how long are you doing live recording?