The solution as i see it would be to enable a 'PVP seeker' or LFB - [looking for battle] status, so that way when a match is close to complete or filling up then it can send you a 'would u like to queue for this match' dialogue along the current number of people on each side seeking to join this match.
Because a lot of ppl like myself enjoy pvping between missions or anomaly runs, but often neglect to requeue after every match - or just get side tracked with quests or working on ship builds. If there was a way to let ppl know when a queue is filling up - there could even be a dropdown box threshold for the dialogue (ask me when a queue is 1, 2, or 3 players away from meeting minimum requirements, along with preferences for notification of Space, Ground or Both)
If this was incorporated I think the queues would become somewhat less stagnate.
The idea crossed my mind when I was in memory alpha crafting and some were complaining about waiting an hour for 1 more person to check the queue and join. It's one of my pet peeves too when i'm in the mood to battle or test a pvp build somewhere other than the war zones.
Mixed teams would be a development for the better, and add a mixed system to kerrat also, there are just not enough klingon numbers and I doubt there ever will be considering your average mmo player wants to be kirk/picard etcetc.