Here to help, man. Glad you find some of it useful. I'd also be glad to grab lunch and a coffee with you if I ever find myself with the opportunity. Strangely enough, right now, I'm a professional close-quarter combat instructor to specialized military and law enforcement personnel. You can read some of my blatherings on the subject over at www.rumsoakedfist.org, the web's main forum for internal martial arts. Also a recovering neurophysiologist and landman in the oil business.
Occasionally, I do custom production and recording consulting for certain client artists in the music biz.
Good tone targets with Nuno, Howe and Vai. I'm also glad you noticed the difference the cab can make. I've maintained for years that for modern electric guitarists, we play the entire rig, not just the guitar......from the choice of pick, strings, action, pickups, guitar pots, cords, OD's, amp preamps, loop effects, amp power amps, speakers and cabs. The whole thing is the instrument, not just the guitar. Any one of those elements can have a noticeable effect on tone. The right choices for each of those elements can mean the difference between so-so "kiddy" tone and superlative professional tone.
As to your parametric EQ settings, I might suggest you try widening the Q of your 199.5Hz and 817.5Hz settings and narrow the 1.5kHz setting. Here's why: the mud frequencies can occur anywhere from about 180Hz to 300Hz. It's not limited strictly to 200Hz. The 817.5Hz represents the middle of the mids. Widen it a bit and it will bring all of the mids up, along with their varying harmonic content, including some of the 1.5kHz. The 1.5kHz represents the upper range of the mids. Bringing it up a bit can give a noticeable, Marshally, harmonic bite, but raising the frequencies above 1.5kHz starts quickly getting into more shrill, trebly territory that's usually best governed by your amp's basic treble knob.
As an alternative, you might also try boosting 100Hz with a very narrow Q, cutting 200-250Hz with a slightly wider Q than you've got now, and boosting 800Hz to 1.5kHz (experiment with where it sounds best) with a fairly wide Q, with the Q narrowing the closer you get to 1.5kHz. I'm also assuming your Xotic BB-AT is still in the pre-gain signal path? If so, it's very easy to use the settings I just gave and use the BB to boost a little bit more of the uppermost mids if you still need to, giving you the 100Hz bump, the reduction in 200-ishHz mud, the singing 800Hz mid-boost, and the sizzling higher harmonic definition of 1.5-ishkHz uppermost mids that helps cut through the mix.