Hi Sharke,
Personally, if I can be honest with you....I think you are being overly anal and over-thinking things. :)
I like the sound of this track as it is. What I would do here.....it needs a little eq for some sparkle...high pass 200 and below...see how it sounds. If you need a little more low end "girth" try high passing at 180 or 150 Hz.
Next, for the sparkle....you get treble on a guitar from 3-6k. Experiment there to see how it sounds. If it literally sounds abrasive, try 8k to just add some presence. It may add a bit more of a "noise" type sound than a presence there, but try it just to see. If it's too hissy, drop down to 7k or even 6.5.
From there, try removing a little 640 Hz. This will take away some of the mids that may be adding to the masking or guitar congestion that you mentioned within the vocals.
Lastly, once you have everything where you want it, use Perfect Space and run a small room/medium room impulse. Eq the room using the PC eq or a Sonitus. High pass the low end until you no longer hear any low end "whoom" type artifacts. You may need to take the HP to 300 Hz. Leave mids alone and experiment where you want the high end in the impulse to be. Again....same set of rules as we had for the guitar eq. In this scenario though, you very well may need to use the upper end of the frequency band and may end up boosting or even cutting 7-10K depending on what type of impulse you used.
These things right here should give you great results. You have a strong recording.....like the frame of a house. Now it's up to you to "dress it up".
Now, the thing with "framing" to get a good sound depends on the mic, the placement of the mic (which I think you nailed pretty good) the guitar and the execution....how things are played. New strings is always super important as well.
That said, a better guitar is going to improve the sound 10-fold. Your playing is good enough do there are no issues there. A really good mic is going to make the sound more pristine unless the guitar is pure crap.
Most really good mic's accentuate what is presented to them. A great guitar with a great sound....the mic will make it sound that much better. Bad guitar with a so-so sound...sometimes the better mic can bring out the flaws more. It's a grey area really.
As far as rooms go....I'm probably one of the only recording guys that swears the room doesn't make a huge difference unless it is a horribly bad room. The reason I say this all the time is because I have recorded in some of the crappiest situations known to man and I have ALWAYS come out of them with an acceptable production. Do good rooms make it easier? It depends on what one calls a good room. The ones I have called good rooms were only good when we could utilize them and create some space with the mic's used. Even there...we had to be careful because the sound + the room (in that order of importance) is what I'm after. I never need the room to dominate the sound....so by the time I get done, there may not be that much room included in the print....even if the room is a good one.
When a room is bad, you use the right mic, you keep it close and after a successful print with the right execution, you manufacture a room that suits the sound. I say that because if you close mic, the room is not going to come into play unless it really reverberates or has rattles that can be heard even when you close mic. This is slim to none in a CM situation of no more than 4-6 inches. With the capabilities we have today, capturing a room sound is only as important as we want it to be. Seriously man. With the power of today with impulses and the ability to compress, eq and color a room, I'd bet all that I own that when done right...no one could tell the difference.
Is a room important? Only if you want it to be. See in my experience, I would only worry about a room in the case of looking for a specific sound. When we need drums to sound a certain way when using a real kit, we go to a studio that excels in drum production due to the room. That said, there aren't many bands today that are using big drum rooms....most drum sounds are in your face, hybrid sampled and the rooms are hybrid as well and half manufactured.
With instruments that we mic....we really need to cover all bases at all times so that we always have a safety net. If it's for yourself, you can experiment until the cows come home. When you have someone paying by the hour, you can't afford a bad take due to a room so you mix and match for the situation. Most times in my real life recording experience (based on genre of course) we wind up using LESS of the room and use more of the direct recording sounds at all times. In some instances, the client liked more room sound and wanted more synthetic added in as well. The reason being...some people don't like to be so up front and naked. They feel room or effects help to mask their flaws when in reality though some of that may be partly true, they are degrading the recording with washout.
So in my opinion brother, unless you get a new guitar and a super sensitive mic (or use a completely different set up) you got what you got....and I happen to think it's quite good. With a few little tweaks, I see no reason how this sound would not stack up against anything else out there. But that's just my opinion. :)
-Danny