I usually would check tire pressure, oil and other things before the long road trip. I did most of them other them the oil level as I thought it had been over-filled anyway, why bother to level the car and check? This's definitely my mistake as who would have thought a Toyota dealer would botch a simple oil change job! As for checking the oil leak, there's an under-cover and I won't be able to see such slow leak unless I take the cover off. I guess we simply can't trust any jobs done by the dealer, which is very unfortunate!
I was surprised that with less than half of the total oil capacity in the oil pan, the low oil pressure warning light didn't illuminate. Hopefully the compression test on cylinders turns out to be fine, although now I'm worried that the tech may screw up something during the compression test such as over-tighten the spark plugs *