As I see it now, and if FGCom servers will be updated to be compatible with both FGCom 3.0
and older clients, FGCom will be all ok,
except for two things: unrealistic radio coverage and, much more importantly, the extremely unrealistic fixed set of radio frequencies all coupled with the range to a fixed position.
That last thing, practically only having ATS frequencies (ATS as in ATC, ATIS etc), is something I have disliked for a loong time. If you can get rid of that limitation
and have mumble not use any bandwidth for a tuned channel while not spoken on, I would say you will have something great coming up.
Something I sometimes daydream about is having a 121.5 MHz and/or 243 MHz guard frequency tuned in on one radio, having one VHF and one UHF radio with separate PTT:s or why not, on transoceanic flights, a HF or satcom radio.
One of the things I do for fun is interception, and as far as possible by the book (see
wiki article). Three of the things missing is getting intercept vectors over UHF or data link, having a transponder to turn from mode 3A or 3C to mode 2* in order to not set off an
TCAS alert and announcing the intercept on 121.5 MHz before switching over to another frequency, usually an ATC frequency I guess.
* These days from mode 3A, 3C or S to mode 4 or 5 I guess.