Triple shots give you both coils series, both coils parallel, and either coil split. To replicate that with mini switches, each pickup needs one 3-way for series/split/parallel, and a 2-way for selecting which coil you use when splitting the pickup. However, those split selectors will also act as phase reversal when using combined pickup positions (in your case that's positions 2 and 4 on the 5-way switch), which is something you don't get with the triple shot rings.
So with the single coil tap switch and the switch for the Graph Tech system, that's a minimum of three 3-way switches and three 2-way switches, plus the pickup selector switch.
Your push-push pots can do the job of the two of the 2-way switches, which leaves you drilling holes for three 3-ways and one 2-way.
That's if you want the full lot. Splitting both humbuckers to either coil, phase reversal on both, series/parallel on both, tapping the middle pickup, and the Graph Tech system. Six switches in total. Obviously if you do want to keep all those options, just using the triple shot rings will be much easier for you. Then you'd only have to drill for the Graph Tech 3-way; one push-push pot would handle the middle pickup tapping, and the other could be used for phase reversal on one of the humbuckers, or even phase reversal on the middle pickup.
Personally, as someone who has too many guitars with too many switches and ends up always using the same two or three settings, I'd ditch most of that.
I'd use just series/parallel on the bridge humbucker. That's one 2-way.
I'd use just splitting on the neck humbucker, and only ever to the north/neck-facing coil. That's another 2-way.
Your pots have those covered, so that means you only have to drill two extra holes, one for tapping the middle pickup and one for the Graph Tech system.
That will still give you:
Bridge series
Bridge parallel
Bridge series + middle
Bridge series + middle tapped
Bridge parallel + middle
Bridge parallel + middle tapped
Middle
Middle tapped
Middle + neck series
Middle tapped + neck series
Middle + neck split
Middle tapped + neck split
Neck series
Neck split.
+ Everything with the Graph Tech AcoustiPhonic
I love out of phase tones and wire most of my 2-pickup guitars with one out of phase permanently, but I wouldn't bother with it for a 3-pickup guitar. Out of phase sounds are most distinct when you use the neck + bridge pickups, and when they're mids-heavy humbuckers. When you start involving splitting or parallel wiring you lose some of the mid cancellation which makes out-of-phase worthwhile (it's really the entire point of it) and you end up with a gigantic volume drop. When you use middle pickups in place of either the neck or bridge (as you do with a 5-way switch) then there simply isn't enough of a difference between the two pickups (bridge + middle or middle + neck) and you get the same result as before, no real depth to the sound and just a very quiet signal that sounds like you just lowered all the gain on your amp.
So, as much as I like out-of-phase, I wouldn't bother with a 3-pickup guitar. You just don't get much out of it. Leave it to the Les Pauls and archtop guitars.
In terms of series/parallel and splitting, personally I find myself always preferring series/parallel for the bridge and splitting for the neck. Additionally, every time I use splitting with a phase/coil selector switch, I end up always preferring one coil over the other, usually the one which is closest to the neck. This is more down to personal preference, but because wiring in all the options gets so complicated, I strongly advise you to choose one or the other for each pickup. I find it very unlikely that you would actually end up using series, parallel, split north and split south for each pickup. You'll most likely end up just wanting series + one of the other three options. So save yourself some wiring and just do a series/parallel or series/split switch.
The Pearly Gates splits fairly well, though you should expect to get very low output from it in that form. Parallel wiring it results in even lower output, so it won't balance with the other pickups at all; splitting to the coil closest to the neck will retain reasonable output best. The Custom Custom both splits and works parallel very well, and should match output with the middle pickup almost exactly. Series/parallel would be my choice for the bridge, but splitting will work just fine if you prefer.
I think I'm repeating myself now so I'll leave it there. :icon_thumright:
Edit: just anecdotally, my 'default' all-rounder guitar has two humbuckers, with one series/split switch controlling both of them, and a phase switch which doubles up as letting me choose which coil of the neck pickup to use when it is split. Despite these options, I basically never split the bridge pickup, change phase, or use the neck pickup series. I may as well just have a simple H-S guitar with no options except the pickup selector. All those options seemed like a great idea when I first wired it up, but you quickly get bored of the novelty and will settle on one configuration.
I also have one of the auto-retuning Gibson guitars, because I thought it'd be nice to switch tunings without switching guitars, but I always leave it in the same one tuning all the time...