don't mean to be a dick about this but you do realize (if you mean what I think you might mean by this) that this has to do with technique, some with guitar and string selection, a little bit of mic placement and nearly nothing with post tracking EQ
it is possible that by attempting dual mono or pseudo stereo you generated phase issues that muffled the very things you want to accent
for a single, intimate, acoustic instrument tracked with a single mic with goal of presenting that performance as accurately as possible there should be virtual no post tracking editing needed . . . you either capture the performance or you don't and best place to 'fix' it is prior to hitting the red button.
I'm not suggesting that you not experiment with all sorts of settings (including things like copying track, notching some arbitrary frequency band, inverting it, delaying it to attempt some sort of pseudo stereo . . . then slathering on obscene amounts of digital reverb . . .) you have to cross boundaries to learn where they are
blending multiple instruments from multiple performances, in myriad spaces, over days, weeks, months; comp'ng a single track from elements of multiple takes and attempting to 'mix' all of this into some type of coherent 'whole' (though sonic profile of that whole can vary more then actual raw material) is where all the tricks of studio magic come to play
yet again when you are recording your own material, with your own performance, are not comp'ng from multiple takes with the goal of presenting the performance as accurately as possible one really should get over the idea that there is anything to 'fix' in post. Reason for this isn't merely hubris (on my part) but the initial A/D capture is as accurate information as you have . . . anything you do to it from there constitutes degrading that signal. There can be nearly infinite list of reasons to do this . . . but all the techniques involve compromise . . . trade off's, you always lose something, you always introduce artifacts and thus work best, are most successful when blending multiple tracks or (OR) when goal is to NOT sound like the initial performance!
While on one of the half dozen forums (or sub forums) on which you solicited advice you stated categorically that you were cognizant of 'mic placement' fact is nature of questions suggests that this is an area to return to for remedial attention. I'm fairly certain I've been doing this stuff for longer then you've been alive (not a boast just the sad fucking truth) and while, in that time, I've placed more then one (or two) mics I'm not sure that I'd consider myself to be an expert . . . every instrument, every room, every performance is a new and typically unique challenge as soon as I slip into arrogance, assume I can just slap mics where I've used them before I end up having to re track stuff I would not have had to, if I'd taken just a little more time up front.
If you take the time . . . record, move mic re-cord . . . learn to hear the subtle as well as gross differences then you learn the instrument, the room, the mic and how they interact . . . and process gets quicker and easier . . . don't take the time and in twenty years you will still be trying to fix in the mix (even when there is no mix)
Now . . . for detailed finger picked (acoustic guitar) transients (that hit of the root) a LDC tube (and certainly not a cheap one) would not be my first second or third choice. Generally speaking small diameter (condensers) will be more accurate (if less forgiving of room artifacts) Additionally cardioid patterns will by design be less accurate and can introduce instrument room interactions that can interfere with transient detail (hit that root)
Then to top it off you indicate that you are in the near field of the guitar (roughly speaking anything closer then two feet though the near not near boundary is fluid . . . but (again generally speaking, specific projects can and do call for very different options) if I were using the mic you indicate (though I don't have any hands on experience with it) I doubt I want it any closer then 18 inches)) 5-6 inches for any
acoustic guitar (do a cursory search of the wave length of open low 'E') is pretty damn near . . . so even very small changes in mic position and focus will change the sound significantly
(then to reiterate by doubling, panning, smearing with verb you are more or less guaranteeing that you are going to lose detail in the transients . . . (the hit of that root!) so? well stop doing that if the 'hit of the root' is what you're looking for . . . no amount of post eq is going to help . . . )
I quite frequently use LDC cardioid (K47, C12 capsules, or variously a ribbon) . . . I think
acoustic guitar was designed to interact with the 'room', an LDC (or ribbon) can add a dimension to capture of that interaction that is at least different from SDC's . . . this is added because there is no single 'right' way to do any of this. You could use the same guitar, in the same room with the same mic, at the same humidity and temperature as your performance you say is general target and the recording would sound very, very different (as it should . . . otherwise this would all be Rock Band air guitar) . . .
with the goal you've set for yourself your primary tools are instrument, room, mic and anything you do in post is indicative of something that did not go quite right whose influence you are trying to 'mask' . . . with your stated goal the less of this you do the better off you are
that said it is unusual (but not so unusual as to be worth my making a diary entry) when I do not use a little compression (these days seldom more then 2:1 slow attack 33 ms (though this can vary with instrument content and performance technique, 100 ms release, seldom meant to effect more then the 'peak' 6 dB) and I at least think about rolling off some the below 125, or 100 or 80 Hz. Both of these are addressed with idea of smoothing the entire performance, as an entity distinct form any individual note. Once those are executed they might not necessarily be retained . . . I try it then recording might not need even that . . . partially dependent on what the product market is . . . format of finished 'product'.
very, very, very roughly speaking if you don't like the roughs either your actual goal is different then what you think it is or there are issues that should be addressed before the 'mix' with single performance with single instrument via single mic any 'mix' is an artificial construct
if it is your own material for your own edification just go back and retrack it until it sounds like you want it to
While I still believe that respectable mics capture transients with greater fidelity (detail that hit of the root) then any p/u transducer I've heard, there is nothing the matter with mixing and matching mic's with p/u's. If you are thinking of playing out then DI and pickups are quite valuable tools. I go back to D'Armond magnetic p/u days and have used most commercially available systems since. At the moment I'm pretty OK with K & K systems (have several including piezo only as well as piezo + mic with K & K's preamp) But you will spend roughly the same on a pickup + preamp system as you would on an entry level SDC . . . AT4041, 4021, 4051, 4051a . . . get an MXL 603 and replace guts and capsule for $219 (a guess). So for roughly $300 you cross the threshold of functional in way that cost me $2000 when I started (and that was when I could buy a pick up for $1000)
but, yes, some form of DI can provide detail for transients more difficult to obtain via mic & room
in any case good luck with it all