What are you digging on Outside Bass Drum?

yeah if I had to guess it's likely a modified 4011a to take the higher SPL. 

It’s funny because I almost never hear anyone talk about the N/D 868….for years and years I wasn’t happy with anything on outside kick. The 868 just sounds right to me.

like i said, I'd bet this is a modified 4011a to handle the higher SPL. But frequency response wise it's pretty flat. Small lift at 10k is all which actually looks more like a 4041a. I'd bet that you could use this thing probably in a LOT of other ways that just a kick drum mic.  

As someone fairly new to the engineering side of things (but MUCH more than experienced in the drumming-side of things), how much weight is given to things like just swapping out the actual kick drum, or moving whatever mic you have around a few inches, etc?

I have basically every kick size and shape available. What does something like a Fet 47 offer in the final mix that tuning the correct drum combined with mic placement and EQ can't overcome? Does it come down to an engineer's familiarity with a given mic which leads to faster mixing and results?

Some more thoughts around this but not directly answering any of your questions, I guess. More like...audio engineering musings around your questions, maybe?

The right instrument with the right preparation (tuning, heads, sticks/beaters) is always step one. Tweaking the right instrument with the right preparation (tuning, heads, sticks/beaters) is often for me the last step. Sometimes you have more options than others. If you have every kick size, bearing edge shape, material, and head choice available and the time to try 'em then you're going to be in a great starting spot and have lots of options for tweaking it at the end.

For better or worse, though, mics are necessary for sound capture and are absolutely not transparent in capturing that acoustic sound you've crafted.

Mics are basically unreliable narrators giving their subjective opinion about the sound of the drum...and that opinion can change if it sees something from a different perspective. A microphone's opinion will inform the transmission of the sound of the drums to the recording medium so choosing the right microphone and position will provide the conditions to give us a favorable-to-our-intentions audio opinion of that really acoustically-great-sounding kick drum.

If the mic has a good vocabulary and likes describing a detailed scene then you'll get a detailed account of the kick drum.

If it is a little more focused on certain aspects of sound or has preferences about the sorts of things it will tell you about, you'll get a detailed description of those certain aspects.

If it's prefers to sit back, space out, and let the sound wash over itself then the description of the drum will be a little more blurry but full of whimsy.

Different mics in different positions are going to have different opinions about tweaks to the initial sound. I think a lot of people rely on a few different mics for the different uses in an effort to minimize variables and nail down the quickest ways to get where they intend to go. For example: an SM57 will never give you strong and tight 40Hz or a really beautiful capture of 3kHz. But it can give you a great 80hz and a really forward midrange sometimes with the downside of being really fluffy in the 300Hz area. My AT4040 gives me great 60Hz plus a good knock in the 800Hz area without seeming too pokey or forward or fluffy. That knowledge in my back pocket, I pick an instrument that makes the sounds to fill a role in an arrangement, I pick a mic that is flattering to the instrument's ability to fill that role, then I tweak the instrument again to make the result of the instrument and the microphone work even better in the arrangement.

That was a lot of rambling from a person who doesn't feel like editing an EP's worth of guitar tracks right now...but he also knows he has to get back to it soon. My apologies if that's a really scattered bunch of ideas or if there are too many different metaphors flying around. Just a peek into my scattershot brain desperately trying to entertain itself and distract itself from editing guitars.