need help with a project bass, a few long questions

[Sloth_Adelphi]

I just recently defretted my old squier p bass and put '62 fender pups with 2 new 250 k solid shaft pots and a new input jack, as well as new tuning machines and a new nut. I read as much as I could on soldering and wiring for these pups and did everything myself. I put the bass back together, (strung it up with rotosound swing bass 66ld strings) annnnd so here is my list of problems:

1.) the volume and tone knobs are extremely "hot" or microphonic, ( to me that means there is that constant static hum and when i touch them there is a pop and the static hum gets more intense) also the input jack is off and on when plugged in (meaning the the signal clicks from on to off depending on how the cable is hanging, etc.) I'm assuming this all means a grounding problem because the pups do work...i can post pictures if need be.

2.) after i tune the strings (i am just roughly tuning them using 5/open for the time being) and play on them for about a minute, they all seem to go flat. there is a number of things that could be causing this and this is why im asking you all, to see if you can help identify the problem:
(a) the new tuning machines i installed required larger holes in the headstock, so i used a bit that looked to be a perfect match, as it turned out, the bit was either dull, or had a chip or something because a couple of the holes were not circles, but more like rounded triangles, which sucks but i made do the best i could by using makeshift shims and woodglue to hold the sockets in place in the hole...which leads to my next problem...
(b) i cracked the headstock along the bottom left, i "fixed" it with wood glue and a couple of screws, it seems to have worked, but it could prove to have not...
(c) the nut i used wasnt the same width as the fretboard, its about 1/16" short on either side. i had to file the bottom of the nut down to fit into the slot, and it fits perfectly, its just not snug, so without strings it falls freely out of the slot.
(d) i did my best to eyeball the saddle heights so that they matched (as best as i could get them to) the curve of the fretboard as well as the relative height of the nut. there is also one screw missing (out of the possible 5) at the base of the bridge.

so please someone who knows more than I explain to me what each of these things mean and how i can fix them. thank you so much in advance!

(p.s. I know those of you with experience and a chip on your shoulder will probably want to tell me first how much of an idiot i am for doing most if not all of the things i have listed...and you would be justified in doing so, but please, i am simply trying to learn how to do this so any and all heldful constructive advice would be immensely appreciated, thanks for reading all of this if you indeed have and please god somebody help me i really want this thing to work! )

[Sloth_Adelphi]

P.P.S- I apologize if any of this information can be found elsewhere in this forum, but I assumed I would just post it all anyway because these problems seem to be specific to my situation, again, thank you.

[Bass]

Gosh! You've got some work ahead of you. I think it's a pretty good idea to remove and replace guitar parts, even if you've never done it before. That's probably the best way to learn.

1) Wiring: try again. I find soldering to be very tricky, and if the solder joints aren't "just so" you're bound to have problems. I "tin" both parts before making the join. For example, I apply solder to the pot, then I apply solder to the wire, then I clamp the two parts together and apply heat with the solder gun and a bit more solder. Be sure the gun is hot and the tip is glean. I give the solder gun a quick wipe with a damp cloth every so often.

You shouldn't have to apply heat to the joint for too long - only a second or two. A good joint will appear smooth and shiny. Be careful not to get the pots too hot, or they may fail and need to be replaced.

You're probably on the right track: grounding may be an issue. Post a photo and maybe someone can help.

2.) (a) Tuners: You're tuners could be shifting around just a bit. Did you use a drill press or a hand drill to make the holes? I suggest filling the holes and drilling again (with a sharp bit). Maybe someone else can explain how to fill the holes. If you don't have a drill press, there are attachments for hand drills that help guide the drill straight.

2.) (c) Why not use a nut of the correct length? This will look better, and the string spacing will suit the fingerboard. Use a small drop of "crazy glue" to hold the nut in place.

2.) (d) Replace the missing bridge screw, and be sure all the bridge screws are snug (don't strip the heads).

[Hambone]

As far as the wiring, it sounds like you've got a polarity problem somewhere - usually, if you've got a buzz, it quiets down when you touch the strings.

[Sloth_Adelphi]

Bass- thanks alot for responding, hah and yes i have alot of work ahead of me but why not right? how would i be able to tell if the pot was damaged by the heat? also, would it have been smart to use flux? cuz i didnt, if so then oops. also, would filling the holes in the headstock really work? i contemplated that but didn't know if the filler would be strong enough. i plan on getting another nut, i was just curious if that could be adding to the "intonation" problem, obviously if i take care of everything i assume it should get somewhat better. and yea i will attach a picture of my wiring job so that you or anyone may have an idea as to what may have gone wrong. thanks again!

ham- what is a polarity problem and how do i identify/fix it? thanks for your help as well, advice from you is much obliged.