I don't bother with matching inclines/declines for orbital transfers.

This is fine. It would be better if you manage an encounter near the AN/ DN. Matching inclinations first, though more expensive ∆v wise, allow for an easier time planning encounters.

What is the ideal capture?

Go close but not too close. Closer means more ∆v saving by taking advantage of the Oberth effect. Too close will make you crash. Mun peak is 7km while Minmus is 5km. However, aim for around 20km as you do lose altitude when you burn retrograde before periapsis. Also, you cannot timewarp fast too close to the ground while scouting for landing spots.

I have a hard time with gravity turns. Right now my strategy is to just punch straight up as fast as possible and when I hit the thin upper atmosphere and get "free reign" so to speak on maneuvering then I worry about turning and direction.

And this is where your space program is hemorrhaging money. I'm guessing you added an extra stage to top-up ∆v to punch the sky then circularize. Do many to all of the following to make your craft more aerodynamic/ more controllable: Cone shaped rocket (small on top, large + heavy at bottom); Symmetric rocket; Add nose cones to top, fairings to unused stages and fins at bottom; Add reaction wheels; Add struts; Don't accelerate too fast at lower atmosphere (TWR ~1.5); Don't make sudden turns (stay near prograde).

For orbits most guides I see say push for 80km or even 100km but I typically keep them tight at a little over 70km.

You're fine. You don't lose much transferring to Mun/ Minmus, but you lose all of it going interplanetary.

From the Mun returns I didn't bother with establishing a low orbit first like all the guides say.

If you craft powerful enough (out of Mun SOI in minutes), your method is better. But if it is not, circularize first.

I tend to "aim high" at Kerbin: 40-50km.

You're doing fine.

Is it cheaper in delta v to just 'hit' Mun or Minmus...

Same either way.

When I orbit Mun/Kerbin for landing if I can spare the delta I try and move my apopsis over my landing sight.

Mun - Your periapsis should be very near the surface and a little over your landing site before the retrograde burn to stop. You lose ∆v by burning up countering gravity to avoid landing too fast. The shorter this phase is the better.
Kerbin - You trajectories mod.