Powering Pro Mini and adaptors from custom connection

So I have some pro mini 328 (clones), and I want to power them in a few different ways, as well as some ethernet adapters that need a 3v3 in. For testing purposes, I am powering everything off a USB to TTL converter (here), using the 5v for the mini, and the 3v3 straight to the vcc on the ethernet adaptor (here)

So to power the pro mini (here) directly from the power pin from a usb micro plug (here), I presume I can just put it in the RAW pin? I would then want to also power the ethernet from this plug, so how do I convert from 5v to 3v3, do I just need a regulator? This would probably be coming in at 2A as well, would that make a difference?

Another thing that I want to do, is use an ethernet cable and plugs to connect a bunch of pro minis as water sensors outside in an aquaponics system. So I was just going to use the micro usb in (2A) and send it down one of the ethernet wires, using the others for data, ground etc. This could be for a distance of up to 15 meters or so, and then into up to about 8 pro minis. What would I need to do (power wise) for this?

Hi, welcome to the forum.

I can’t believe that the usb-serial adapter can supply enough current for the Ethernet module.
Those adapter can perhaps give 30mA at the 3.3V pin and the Ethernet module might need 200mA.

Perhaps you can buy 8MHz 3.3V Pro Mini boards, and run everything at 3.3V.

For 3.3V you need a voltage regulator. Use a LDO (voltage regulator with low voltage drop).