#2
A UG column belongs specifically to Ultimate-Guitar.com and the author in question. The first step is to contact the author directly, who can likely contact the website.

Otherwise you can't do anything with it.
#3
I would contact the author and get their permission firstly, and their full name. You should cite the date you accessed the source and the location of said source.

I imagine it would go something like this:

Contrary to popular belief, guitars players are not all great lovers - it's only those that own Statocasters that can properly satisfy a woman. (Smith 2010)

Smith, John Q. "The truth about been rooted by a guitarist." Ultimate-Guitar.com. 30 May. 2009. 21 June 2010 <https://www.ultimate-guitar.com/forum/showthread.php?p=24481702>.
Marshall amplifiers are the truest purveyors of rock and roll known to man.

"And give a man an amplifier and a synthesizer, and he doesn't become whoever, you know. He doesn't become us."

Holy crap, check this out!