1995 BMW 540i BMW 540i

O.K. I have a 1995 BMW 540i, 135,567 miles on it. It really runs good. A few things I'm just curious about because I don't know everything about this car yet, I'm learning a lot from what bmw techs say and from what I've read.

1) I have an oil leak, not real bad, just wondering why no one told me, I had to find out myself. Told me that I had coolant leaking and was about to change the thermostat myself. Felt like sense the radiator is pretty much brand new it's probably leaking in the in-take because I didn't smell or see coolant on the ground. Should I change my thermostat? It's been over 6 years considering the history.
2.)Just got my front struts on and it feel so wonderful, feels like i'm riding on a cloud. The mechanic that did it had to shave somthing off on the passenger side. He said that somthing was beaten up so badly when I was driving on the bad struts that somthing got worped. It is now make some noise like somthing is rubbing against my wheel or roter. It sounds like grass-hoppers rubbing their legs together, especilly when I'm coasting. What is that?