The OCD is real. I'm not looking for perfection per se, but I like to be confident that things are "ok". Sometimes going down the rabbit holes is detrimental to my OCD tendencies.
"It takes one to know one" similar to "If you spot it, you got it"- I have bouts of misguided OCD and I'm detecting it in this thread.
Here's my synopsis:
The front wheels do a lot more of the braking than the rear so they're gonna be hotter. That small difference between the left and right could just be the testing equipment or method of use. It's too small a difference to ascertain a mechanical problem.
That hose being off caused a large vacuum leak which would cause your high fuel trims and corresponding DTC. As you see, there are three levels of DTCs- pending, stored ("confirmed") and permanent. Pending means the PCM sees or saw a condition (usually
conditions as there's often multiple symptoms involved) where a sensor reported out of allowable range and it is monitoring it to see if it is a standing issue or was "just a one-time glitch". Issues that can be caused by somewhat unique, but still normal driving conditions are often given these "second chances" before the PCM determines it is an actual fault. If the fault remains through X drive and/or monitoring cycles, then the PCM stores a DTC as it has now "confirmed" there is a problem. These can be cleared for further diagnostics or after the fault has been resolved. A permanent DTC is usually reserved for emissions faults. You can't clear it with a scan tool. The fault has to be resolved and the PCM must not see it again for X drive cycles. If the fault doesn't return, the PCM will erase the permanent code.
As the others have said, most of these things are normal items for such a vehicle at that mileage. If the PO had maintained it better, all of these issues wouldn't have been present all at once. I think you might have set your expectations just beyond reality in the sense of "I've put X money and labor into it, therefore, it should be perfect". Any time you install used/refurbished parts you're at the mercy of the refurbisher and they make do mistakes. The installer (you) could've made a mistake or two, compounding the problems. I wouldn't get too hung up on the total amount invested. If you had bought one that was totally up-to-par and needed nothing, you might would have about the same invested. Good luck finding such a rig.
Take a breather and focus on it when you're ready.