Looks pretty normal to me! Just need to hire a grease vent cleaner to cut holes with a power washer, and spray a solvent to dissolve the remaining roof. Just completed some repairs on a Mc D’s that had 1/2 of grease running down the roof towards the drain.
Grease destroys rubber and asphalt. You can get a special kind of rubber called Epichlorohydrin that is resistant to grease and put around the one on the rubber.
In general though they need to clean out the grease traps more often, if they have ever been cleaned at all that is.