On the topic of voice, for PC everyone says they want it. In reality, a tiny percentage (single digit if data from other devs we speak to are to be believed) of people use it and most people have their own preferred third party solution (Discord, Vent, TS) that their usual organizations choose.
There's a couple of improvments we could look at (and are discussing):
1. Deeper discord integration - Even before this is a thing, we will be highlighting discord much more prominently in the launcher and in-game. Whether or not we can do some deeper auto integration is for exploration later..
2. Steam voice support - Fine if we're only ever only going to be on Steam, but that is a bit of an open discussion too.
3. Vivox - cross platfrom, but very expensive for us to use and host and almost never used on the games that have impiimented it.
In short, stay tuned, even if we do nothing more than better promote Discord (and I hope at some point we have some cycles to do more), it will get better.
On your overheat suggestion, 1.12.1 will have the first steps toward breaking the "heal ball". Some details are here but there will over time be many components to this effort that will once again cause the meta to evolve. Please don't view this as "we're nerfing healing" because we're not. Aside from revisiting some kep officer briefings and modules. We are planning some changes to beam weapons that will make them more interesting and more strategic than the role of tac cruisers have today. Our combat designers are planning some upcoming blogs to keep folks in the loop of the changes that are coming on these and other balance related fronts.
Matchmaking - as it stands today, players have a fleet rating, based upon the ships they have in their respective fleets which. Hard divisions between tiers will only serve to fragment what is already a relatively small matching pool (more than 70% of players online at any time are in a match, not eligible for matching). In short, we don't have the playerbase to support such a structure. A larger matchmaking pool in general (which Steam + more languages should get us) will help keep the real legendary players up in legendary (where the battle bonus is much larger), away from the real vets.
In any event, we intend to reevaluate matchmaking, hopefully taking into account more complex options, including geographic location, some time after the Steam launch (right now all of the people to do that work are working on getting our butts to Steam).