I've actually seen talk about the canons in game a few times. I swear I saw a post here about them hitting too hard but maybe it wasn't in the English forum.

The adjustments don't seem that big to me. Healers are of course very important, but they were already very important, and have always been very important in the larger battle style game modes in this game.

While currently the game seems to be very healer heavy, The emphasis on taking the middle with/against stacked healers is more of an issue than their overall performance throughout the match.

The game encourages players to make use of robots which can't be healed. Fighting healers in lanes isn't as difficult due to mech support.
Killing mamets being healed... I don't think I've ever seen the issue of an "invincible" mamet even while being healed by two people.

The biggest issue I see in the current and original Rival Wings is the emphasis on taking/defending the middle area, system wise anyway.

The biggest issue I see in general is something no balance patch will fix. Lack of understanding the game mode, lack of coordination among teams, and a lack of using the area outside lanes/mid by more than a few people in an entire match. There is also a lack of actual strategy in my DC. It's usually "Push mid, then tower, keep mid,etc." and if a team fails to get mid, usually its a long draw out loss, even if there are other options to overturn the loss.

While I agree the lack of communication on the english side of things is a problem. I don't agree with the things people consider issues mostly in the game mode. The biggest problems I see from the mode aren't fixable with a balance patch.