The tone controls wont be very independent.
nah, the tone pots will only be very slightly interactive. try it and you will see. Remember that a p pickup senses different pairs of strings. A side-by-side humbucker wired in series with two tones will still have almost completely independent controls, but because both coils sense the same strings, you won't be able to tell by ear, without tapping the coils with a screwdriver or something.
I recommend using 22nf caps instead of 47nF.
as for hum, well, the wire you run from the join of the two coils should be shielded. if your pickup only has two single wires from it, you should replace this anyway. you can just go with a 2-core and shield type wire if you like. Or if your wiring is already shielded, then simply earth the braid to the new wire at one end and trim and heatshrink it at the other.
choose either linear or reverse logarithmic tapers.
Don't use linear for tone pots. If you must have "left-handed" pots, use anti-log pots (or "reverse-log", "reverse-audio" etc). These days these are usually called "c" pots, but not always. It depends on the manufacturer.
very few of my left-handed customers over the years, have prefered anti-clockwise pots TBH. They are used to turning up the car stereo, the oven temperature, the light dimmer, mixing desk knobs etc etc clockwise.
If you are leaving out your volume pot, you may want to run a kill switch push-pull for convenience.
I'm not really sure how useful this wiring will be, but hey, if it gets you to your ultimate tone, then I say go for it!
