knighterrant81

Budget? What type of mechanical key switch?

I have my similar mic sitting right at the corner of my mouth and my friend with the 2021 does the same, perhaps you need to move the stand??

Volume is proportional to the square of the distance from the audio source, move the mic closer.
The 2021 is a good mic for voice calls, a close friend uses it as their daily driver discord mic and being supercardioid somewhat ironically the closer it is to your mouth, the less it will pick up your keyboard due to the highly directional nature of the capsule and the way off-axis rejection works.

I'm not sure why you have such a low signal, by all rights the AudioBox should work just fine with the 2021, if it doesn't get much better by moving the mic closer you could possibly have either a dead mic or interface.
 

Do you have stock in Behringer?
I understand they have a place in the market supplying low end equipment at a very competitive price but you got to understand that it is low end equipment and that comes with many problems. such as the poor warranty system, terrible customer support, poor quality control.
The UMC is acceptable at best. Its not good and its not bad and its simple enough that even behringer cant mess it up. It just does the job okay at a very low price point.

BUT the X32 which i do think its a very capable audio desk with great features for the price point is terrible at quality control and breaking.
I have personal experience of about 10 x32 desks. 6 went back to the supply on day 1 because of faulty knobs and faders. And I have had to get spare parts for x32 on multiple occasions (getting spare parts for the x32 is painful). Compared to other sound desks from Yamaha and Digico I have never had a faulty product straight out of the box and I also never need to send them for repair or get a spare part in the 6 years they have been in operation.

I've only had one piece of Behringer gear die on me in my years of working in and running music studios and that was a $20 microphone that 1, They sent me a replacement for as soon as I let them know it was DOA, 2, I fixed myself in about 20 minutes... And 3, I still use every single day. I'm not sure how you find it difficult to get replacement parts for an X32, they're extremely easy to source and if you constantly have issues with things breaking on them either you've got terrible luck or just don't treat your gear right. The x32 is a completely different beast from analogue mixing desks like Yamahas MG (or other) series and much like driving a sports car vs a sedan, the more complex system of course has more points of failure and that's to be expected, just not to the scale you've experienced it at.

I wholeheartedly disagree that Behringer products (especially the UMC and ADA lines) should be discounted as "acceptable at best. Its not good and its not bad and its simple enough that even Behringer cant mess it up." The UMC series of interface are damn good devices for the money and IMO do just as good of a job as the Scarlett line from Focusrite. I've spent extensive time with both series and the differences are minimal except for aesthetics. Marginally cleaner preamps on the Scarlett? yeah sure but there's not enough clean gain to use dynamics or ribbons without an inline preamp and condensers are well and truly powered by both series so the extra headroom means nothing in practical terms, the headphone amp in the UMC line is actually more powerful based on the responses we've had here so there's not even that argument to make. As for the ADA8200, there was a blind test on another forum that found users couldn't tell the difference between it and a Lynx Aurora 16 converter, now that's really something considering the price. 

Again, you sound very much like some still stuck in the 2006ish era when Behringer products were genuinely trash, they've made leaps and bounds since then and I'm more than happy to let Music Group products into any studio I work in.

RAM compatibility is one of the greatest unknowns in the universe. Sometimes it works, sometimes it doesn't, and nobody really knows why. If you're not in a rush to get things working, I'd go ahead and buy two sticks of the Corsair (from a retailer with a good return policy), so you can RMA it if it's not working. 

@knighterrant81
I would recommend to use just one large audio interface for everything (UMC202 or even UMC404 depending on the number of sources you want to record simultaneously). You can't record audio from different audio devices simultaneously. For example, if you want to record your piano and your voice-over, you have to switch between the USB microphone and the audio interface (piano) as a source. If you plug a microphone and the piano in the same interface, you can record both simultaneously as two seperate tracks.
 
For the Surface Pro you could use the free NDI tools. They allow you to send a screen capture or your built-in cameras as a video stream over the network (Scan Converter). Then you can use Virtual Input on your desktop computer to feed the video stream in most applications as a generic webcam input. For me it works just fine via WiFi, but my WiFi is not clogged with large number of devices and it will take a stable connection with a enough bandwidth to work properly.
 
To mount the microphone to your desk, you could use something like a K&M 23840, 23850 or 23860 microphone arm. I don't know what you're willing to pay for somehting like that, but these are some solid options if available in your country.

What sort of music do you teach? The reason for my question is to determine how many inputs you realistically need to get good sound on the instruments you'll be teaching.
Rice is correct, my usual recommendation would be something from the Behringer UMC***HD line just because of the raw value offered by that series but depending on how many inputs you need another manufacturer may be a better option. Focusrite interfaces cost a little more and IMO have better external design (and internal routing software though I've never really felt the need to use it) making them another solid option if aesthetics are important for you. 

If you just need basic 2 inputs (say for voice and a mono instrument) my recommendation would be the UMC202HD, damn good for the money and the dedicated headphone amp is more than decent enough for everyday use. If you're looking for a little more nuanced explanation on interfaces or purchase options (either for mics or interfaces) I've got a decent guide in my signature you might find useful.

As for mic stands, I use a $12 'eBay sort by cheapest' scissor arm on my daily driver PC and it's worked great for me though I am using it with a very light mic (Behringer C2) otherwise I use normal mic stands.

Anyways, if you have any other question I'd be happy to answer them. 

@The Flying Sloth is our resident interface and mic guy around here though. but if it were up to me I would say a scarlett 2i2 is just the reliable pick for me sounds great easy to use. his typical reccomendation is a behringer

ah it seems you need a ADC/audio interface  with a  headphone out what headphones are you hoping to run on them?

I have a Steinberg ur22 mk2 which works well but was a bit of a challenge to set up initially with the software and drivers.  Has dual inputs and phantom power, came with a software download for professional mixing also but it's overkill.  Check out their UR line for what you need.  Also, if you really want to spend some cash, check out "goxlr".

I use hitfilm express and it’s quite good just kinda long render times.

16 gigs for the most part is more than enough for this workload, and honestly this build is more than enough for this workload, though depends on the scale of the project and if it's struggling..
Reslove is a decent free one afaik..

Your ram is fine for video editing. More isn't really needed.