Repair Tool has issues with structures, but usually can repair them.

It's more useful to repair teammates and vehicles anyway though. Use it for that.

I can't second that as people are 80% oblivious of an repair and keep running straight at the enemy. If there are repairable structures around it will help to repair them as any structure can help in its way. (esspecially support station) Additionally it nets you the same SP as a vehicle repair would do. But the triage should go like:

1. Tanks sitting close to cover.
2. Infantry in cover going from Heavy -> Assault -> Scout
3. Installations
4. Tanks in the Open
5. Infantry in the Open

Notice how vehicles and infantry are higher on the list than structures, the only difference being that installations are cover in their own right, and the others are more situational as to when you should focus on repairing them.

Infantry NEAR cover are good to repair as well - but with a harsher Heavy => Scout curve. Also, you missed non-repair-equipped Logi suits as a step between Assault and Scout - although sometimes Scouts are better to heal if they're good... or armour-tanked.

Also, once you start repairing, you can sprint while continuing a repair.

And I wasn't saying repairing strutures isn't valuable, just that, at the moment, repairing other things is a better option, and that's partly because it's more reliable.

I haven't had a problem repairing ANY of the CRUs or Supply Depots on the map - and the only time i have trouble with the turrets is when I'm in a position standing below the "floor" level of the turret I'm trying to repair If it's on level ground, it's fine. If it's on rough ground, get level with it, or standing above the level it's standing on, and I've been able to repair - unfortunately, this often means I have to be out of cover, which is where the problems start.