The electric fan is there mainly to assist the A/C performance. Definitely replace the broken one. The fan won't come on unless the refrigerant pressure is high enough to activate it. It has no bearing on engine temperature until you're well north of 100˚C. If the bent fins annoy you, you can straighten them out with a plastic knife, or you can get a fin rake and get it all straightened/spaced back out like new.

Get that oil pipe fixed NOW. That's one of the infamous oil cooler lines. Google this site for more info. If it lets go and the oil filter thermostat is open, it'll dump your engine oil RIGHT NOW. Damage will occur before you even have time to react/pull-over/stop-engine.

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Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]