Hey Gillian! Yes that's the kinda mismatch I was explaining... As we get more players these won't happen... They do normally play people in their class, but if there isn't anyone then it will matchup someone on each side of you. As we get more players it will naturally fix itself.

On the golds, they can play with the regulars... All of them play and you can play your golds too.

But this brings me to your last point... You are correct about the summoner... but the summoner has a table that will tell you what levels of each rarity can play... So a level 2 rare summoner will play and level 3 common and a level 2 rare and level 2 epic and level 1 legend. Here is the chart for the rare summoners.