The repair/rearm shit isn't making the metagame any dumber, it's completely insignificant. The real metagame will be merc/faction community warfare.
I've been playing the game since before repair costs were implemented. There was a noticeable difference in player behavior before and after repairs were a part of the game. Once they were put in, players started trying to play more tactically instead of the massive single group clashes that were happening previously - taking what measures they could to minimize their own damage taken while maximizing damage done to the enemy, e.g. using terrain to your advantage, hiding behind rocks, surprise flanking maneuvers, etc., instead of just smashing into each other in a big group like they used to. It was also the start of the rise of the LRM-wars that lasted up until ECM was introduced. LRMs made a great way to get in "free" damage at little risk to yourself.
As an idea it's cool, but in reality, in a multiplayer game, most people want to play the stuff they unlocked. Furthermore, nobody really wants a team mate in a match who only partially repaired/rearmed. I'm sure plenty of people at PGI are having a pretty big headache over how to balance clan tech without R&R, though.
If this was a single player game, then all of this stuff would be really important to have, but in a MP game, I'm not so sure.
A very important point and the thing that some of my friends complain about the most - it's not fun to lose money or not be able to play the mech I bought b/c I can't afford its maintenance. There is a certain truth to that, but World of Tanks/Planes are some of the most successful F2P games out there and they run on just such a model. I can see both sides of the argument, but the behaviors of players differ when there's no real penalty for losing/dying. There's also no penalty anymore for bringing expensive, exotic, and what's supposed to be 'rare' equipment onto the battlefield anymore and failing. Why not put that XL engine in? Why not get an Artemis system? Why not get Ferro Fibrous armor and Endo Steel internals? Or Clan tech as ColonelSkills pointed out? The balance
was that it was expensive to run, so you better be winning with it.
I think PGI needs to incorporate the concept of Battle Value into the game, perhaps in a mode w/ respawns. Better stuff = higher Battle Value cost and your team has a limited pool of Battle Value to pull from. I played some game with a system like this recently but can't remember what it was. Take out awesome shit and fail spectacularly with it and your team is going to be hurt by it by consuming a lot of their respawn resources.
Back to the problems that ECM introduced. Ever since ECM was introduced, people just run around in a little ball under their ECM bubble (save perhaps a light mech cadre intending to speed cap the enemy base). Since the enemy team is walking around in a radar-invisible big clump, it hasn't been worth the risk to split up into lances - any 4-mech group that runs into 8 mechs is going to be in a lot of trouble. It's been far more profitable to run around in your own ECM bubble mega-clump. If you happen to smash into the enemy group, everyone rumbles. If you happen to have taken a different path than they did, you attempt to speed cap the base.
It seems with the changes PGI is making they have completely dis-incentivized any action other than damaging the opposing team. There isn't even much advantage to winning anymore, just the Salvage bonus and the fact that if your team won you're likely to have done more damage to the opposing team and thus earn more money. What's the point of a base cap anymore? Why not remove the mechanic entirely?
It'll be interesting to see if tomorrow's patch brings any changes to ECM. The only things we know are that the range of TAG will be buffed from 450m-ish to 750m-ish and the duration of NARC will be increased from 15 to 20s (but it doesn't work on mechs under the effect of ECM anyway...so yeah). I started out on the side of the pro-ECM folks saying that people just needed to adapt to its presence on the battlefield. But now after 2+ weeks of playing with it in place, I've decided it is just too strong. It's not impossible to win against it, but the fact that the team that brought the most ECM has a decided advantage over the other team and the fact that it only costs a couple tons where the only non-ECM counter to it occupies a valuable weapon slot leaves me with the feeling that it needs to be toned down in some respect.
One way to tone down the effects of ECM w/o breaking it would be to remove its ability to prevent enemy mechs from seeing where their allies are. The loss of situational awareness is pretty devastating and it's piled on top of the all the other advantages ECM provides (negates enemy target sharing, prevents target acquisition beyond 200m, prevents LRM lock on, prevents SSRM from firing entirely).
I'm not entirely disillusioned yet, but the path the game is going down these days and PGI's response to feedback (or lack thereof) is not giving me a positive outlook.