You can always level up your summoners, it's just that they'll be restricted to lower levels by the league.
It looks like you were able to combine your Beta Malrics and Zintars. You can't combine Alphas and Beta together, which is probably the problem you were running into.
I'll be making some more basic posts once I get the Facebook page up.
RE: Level 1 Teams for 20 Mana, Aim True