Great responses guys! I see some regarding my potential "improvements", so I'll start with those.
People seem to have mixed feelings about global/server chat, which is perfectly understandable for the reasons provided. The possibility of vulgarity, player disagreements spiraling out of control, drama, etc. In my experience with mobile games that have this setup, there are a few potential solutions. For one, moderators can be appointed in game to police chats, and certain words can be censored. Another option would be requiring payers to pay for tokens so as to speak in world chat, with each post taking up 1 token, and allowing "free speech" in local server chats; censorship is still in effect here. This has the dual effect of forcing players to use their words wisely for a larger audience, and encouraging a sense of community with those closer to them.
Going thru the posts, I like the common theme of more customizability in regard to arena matches that keeps getting brought up. Being able to choose the map if you're fighting friends, being able to see everyone that has challenged you (as opposed to just those who lost), the option to fight your own (AI controlled) primary arena team for the purpose of probing it for weaknesses, Live/Real Time pvp, pvp matching by lvl instead of strength, these are all worthy goals. Some may be more difficult to realize than others, but all would be nice to have IMHO.
I also see posts asking for increased orb, feather, and promotion-related accessibility, all of which sound reasonable in my book. I think FEH has the potential to stick around for awhile, so working with the player base on matters like these is likely in the devs' best interest. Keep it coming y'all!