Yay!
Honestly, you really can`t lose with either account. The beauty of having either Ix or Mileena`s MA is that their neutral element meaning you gain a 1.5x multiplier for any/all story/event maps. That means you can bring them to EVERYTHING! It's not as potent as the 2.0x multiplier you'll received if you match the anima type directly, but I'd gladly take the versatility of it. When I re-rolled, I aimed for either Ix or Mileena and got the former first. As for weapons, I wouldn't worry too much since Ix/Mileena's weapons are available on all banners (as are the ones for other story characters), so you'll get them naturally over time as you progress. Personally, I completed the entirety of the story mode so far (up to Chapter 6), with just the weapon Ix came with. It means I basically spammed DEMONG FANG over and over again, but it worked. Granted this probably won't be feasible for more difficult content, but by then I should have more weapons/artes for him (I just got my second weapon for him this morning on the Edna banner, so at least that's two artes I have for him now).
In-regards to Edna, I'm not sure how good she is but, from what I understand, all MA are basically good. The only downside to using an event character as your "main", is that it's more difficult to gear them up since their weapons are only available in their respective banners (this also applies to their MA, of which you already have). You do have one weapon for Edna which is great, and you'll be able to equip her with whatever else for the stat boosts, but you'll only be able to use the arte on her 4* weapon. Banners do return though, and apparently later on they'll incorporate a prism-exchange system where you trade prisms received from doing multi-pulls for weapons, as well as costumes. Also, I believe the Edna/Mikleo event itself will give you a weapon or two (unless I'm mistaken), so it shouldn't be too bad.
As for which account to go for, that's up to you. You can't really lose with either, so just go with whoever you like more. Do note that Mileena's MA changes her MA from a heal to an attack, which can be a good and bad thing. Good, in the sense that you can use her as an attacker (also, the range on her gacha MA is pretty nice) and not as a healer, but bad as you'll probably need a healer for more difficult content (until you manage the MA for another healer, such as Tear).
Whichever account you decide on, just let me know and I'll add you.
The art looks pretty nice, but I have a feeling it's going to be extremely grindy. I'm not liking the whole paid/free versions either. From all of the past "free" ones I played, at the start it doesn't seem too intrusive, but as time goes on more ads start to appear and it gets really frustrating.
I'll pass, but definitely interested in hearing the impressions from those that play it!
The game isn't super-amazing or anything, but it's still better than a lot of the stuff out there for mobile, IMO. It feels about as close to a genuine "Tales of..." game as I think you can get (given the platform), but will feel a bit simplistic early on, due to not having a lot of matching weapons for characters which grant you the use of their artes. At least you can play as every character without the need to open your wallet, so that's nice.
If you're a fan of the series, I'd definitely give it a second try. If you still don't like it, then it's clearly not for you which is totally fine. This style of game can differ greatly from individual to individual, so it's understandable.