Any general bit of knowledge that I should have on this part of the mixing process?

Yes:

1. Don't use all 4.

or

2. Turn them down

But seriously now, I would pick 1 or 2 of them at most. If you have to use more than one, then pick one with more low end oomph, one with more finger noise so you can blend to taste. The low end gives it balls. The finger noise helps it cut through if there's a lot going on. The more you add after that, the more low end mud you're going to create. But a single track that has the tone you like, with some EQ on it and on the other instruments that are fighting for the same sonic space (i.e. cut one where you boost the other a little bit, or vice versa), is probably enough. IMHO.

Yeah, I should be able to pick two tracks out of four to mix. I like the fingerboard sound that the 414 picks up but wasn't sure which other to go with.

When I was tracking, i liked the QTC omni tucked under the bridge. Now I'm wondering if it is too boomy or muddy. Was wondering if that can be dealt with with eq or if I should mix it with the 414 w/ the m930 cardioid.

Thanks for the response...I'm a performing musician more than a recording engineer so this is a different kind of listening & process...

I'm a performing musician more than a recording engineer

Well I'm neither so you're really in trouble now. Here's what I would do: get a reference track, some tune where you like the sound of the bass from the same genre of music you're recording and where you can isolate that sound well enough in order to really focus on it, and then spend some time listening to it on your monitoring system. Pick the recorded bass track that's closest to being the ballpark. Add in the more plucky bass track. Mess around with EQ and relative levels of the two tracks. Lather, rinse, repeat until it's close to the reference track.

If you're looking for someone to tell you what your bass should sound like, it probably won't happen. So the first step is deciding what you want your bass to sound like, then experiment with a couple of your recorded tracks at most until you get as close as you can. Even better if you can do it with just one. More tracks = more mess, more potential problems to solve.

Thanks. I'll start experimenting. The plan was to mix a couple of track down to one so that I'll have less to deal with. I think that I have decent sounds to start with at least. Just afraid of doing things the wrong way...guess that's what schooling is for.

Thanks for the feedback.