audio recommendations for video-calls with MacBook Pro 2015

[project_2501]

Many of us are now doing business over video calls.

I'd like suggestions for the audio element of my setup around a 2015 MacBook Pro 15":

1. I have a "cheap" DSLR (Sony A6100) connected via an Elgato Camlink 4K over USB-A.
2. I currently use a bluetooth headset (Bose QCII)
3. I have a USB microphone (Rode NT-USB) but it needs to be close so I don't use it.
4. Instead I use a "Boya" cheap lapel microphone that plugs into the audio socket. It works ok but due to the cheap construction it is breaking, and the very long wires get in the way.

Challenges to be solved:

1. The fans run like crazy with this set up - why? How can I fix this?
2. The broken lapel mic has much better sound capture than the headphone mic, the laptops built in mic and the dslr's mic. What should I replace it with?
3. If I go with small in-ear headphones then that takes the microphone socket, so I would need to move the lapel mic to another port - do USB ones exist? Splitters? USB audio interfaces? (dongle hell)