Coming from marvel strike force

I've read the intro guide. I'm pretty high ranked in msf top 5k players in collection power. I know global release for this game just went up. I've been playing it a little bit. What's the content look like for alliances are there going to be raids or just Alliance events, also what are Alliance events, and at what level can you participate in them.

I'm also looking for a tier list of sorts especially for a beginner. I purchased the wizard ysemite, and Im really like the other ysemite with cheer up or royal coyote with OU/DU with combination of wizard and bugs blow ups and a taunt toon.