Always change your own oil. I worked at a Walmart TLE when i was 18. I didnt really know shit about cars back then, and neither did most of the guys who worked there, and half of them were on parol from Arizona state prison.
I have seen them start cars to check for leaks, when there was no oil added to the car do to miscommunication. makes a real horrible noise
Drain plug gaskets, no way. Stripped/overtightened drain plugs, hundred or so, and I only worked there 6 months. Overfills common, and I never saw anyone wipe off a grease zert while lubing or being careful not to get dirt in the diffs/manual trans when checking or adding gear oil.
After working here, and seeing the lack of respect to peoples nice rides, I would never trust a quick lube. They dont get paid enough to give a shit IMO.