- Custom games are already possible to make in Crystalline Conflict right now and that's how people run scrims and LP tournaments. It's Frontline that doesn't have custom game options unfortunately.
- The reason Team Ranked was scrapped a long time ago after only a couple of seasons is because of the rampant win trading everywhere combined with the ridiculously small pool of teams. But this was Feast, a pvp mode notoriously inbred and with a much lower popularity than CC.
- Thinking that allowing a full 5 players premade to queue up freely in any CC mode is not a problem is delusional. If you have played in scrims/LPs or watched tournaments, you'll understand how the result would be a total slaughter not dissimilar to what DRK abusers do in FLs right now. I do however believe that allowing duos to queue up for casual mode only at first, and ensuring that the automatch finds another duo to pit in the opposing team, would probably be a pretty relatively safe first step to try and I find it surprising that SE doesn't seem to be willing to try this out considering that I do agree with the OP: unable to queue with your friend(s) is literally what blocks most of my own social circle from really giving pvp a go...