Hey sorry if my response may not be what you looking for, so you have 2 options with the small server. You can host one yourself but that puts a lot of stress on your PC if you flying with other people like 4+ for example or you can find a small server to join that doesn't have a lot of players. You can avoid hosting on your PC but then you would probably need to pay a server provider and then you dont have to host off your pc but a PC built to host games like DCS in a large scale.
Regarding your question with talking to others and flying, SRS is the best way to go in any situation with communication.Its a built in radio system that works with your planes radio.Lets say the carrier frequency is on 127.5 am if you switch over to that frequency and speak with other players on that freq they can hear that you are "inbound" and things like that. You call out your words yourself to other players, however the AI atc cannot hear this or respond, you will have to do the ATC calls manually. Lets say you and your flight are in flight and on your own frequency you will be able to hear them as long as you are on the same frequency. I dont know how to explain in words i tried my best with the SRS but overall, SRS is easy to install and easy to use and very very helpful.
i dont know much about VR, but i think maybe a different choice to earbuds as the Mic quality may not be as good or clear as per normal while in flight. If it does work and your friends can hear you with the earbuds great use em, If you struggling with them invest in a cheap-ish headset with a decent mic or just a plain mic.
I hope i answered your question in this long reply, if you want any other help add me as a friend on discord and ask away!
Regards
Ethan
EthanM#5048