The economy skill sets the base difficulty for repairing a mech; they don't recover naturally. More difficult repairs add to the base difficulty. So for instance, to repair the armor on a Mad Cat (a Clan, Heavy, Ammo-using 'mech, with an economy of 5) the player needs to roll at least a 6 to repair one point of armor. They need to roll at least a 9 to repair a serious consequence. In contrast, a Hunchback-9P (a medium, introductory-tech mech that doesn't use ammo with an economy of 1) needs to roll a 2 to repair one point of armor and a 5 to repair a serious consequence. The tradeoff is that the Mad Cat is a lot more deadly, but the HBK is far easier to bring back to full after a stiff fight.
The rules are dumped in the sticky All About Operations, where it goes into detail for each of the operations types.
I kind of agree that the mechs don't need many aspects. I put 'Red Paint Job' on the example mech as a joke (Red makes it go faster!) but now half my players have their paint scheme as an aspect for the mech. Which is not wholly bad, but not really what I had in mind.
I did skills the way I did because I know it's fairly easy to wind up with a very specialized character who's amazing at one thing but crap at everything else; since this is a battletech game, I figured all the characters were likely to buff their mech skills as much as possible. As a consequence of spreading the skills out, though, I wound up with a fairly high number of total skillpoints to get the effect I wanted -- a total of 35 skill points, mostly ranks 1 and 2 (8 points in Average skills, 14 in Fair skills).
The way I set the skill pyramid up guarantees that, no matter what, every character has at least a moderate spread of skills, with a couple ranks here and there even in the things they're worst at, and I think that also helps give the characters some depth. The guy who's a great mechwarrior and is also a science nerd is going to be different from the guy who's a great mechwarrior and also Mr. Popular, and they're going to be different from the guy who's a great mechwarrior and also likes to get into barroom brawls...they're all great mechwarriors, but they've got enough supporting skills to differentiate themselves.
I do actually have one character (out of six) who's only a decent mechwarrior, not a great one, but they have strengths elsewhere that'll probably prove significant.