Good write up here. I think it’s got a lot of good points! One thing I say to my new guild mates that I think they appreciate and thank me later is to try and focus on one element for a bit and get that summoner up to level 3 at least. It’s a little hard with the prices being as high as they are but they will come down with the advent of the new set soon. Level 1 cards can only get you so far!
One of my favorite summoners is certainly the wizard of Eastwood. The armor reduction is powerful in a lot of battles!
Agreed, leveling up your summoner is essential to reach higher leagues but in my experience you can reach the silver leagues easily with a lvl 1 summoner (if you have the right cards). So I don't think that beginners will need highere lvl summoners but it's good long-term strategy to lvl up at least one summoner.