When the vehicle is cold pull the radiator cap off making sure that the radiator is full of antifreeze start the vehicle up now if you see bubbles coming up from the antifreeze almost at a regular pace it may be a blown head gasket
The yellow residue is common and normal. It's water from condensation and it easily happens when there are cold periods followed by warmer and more humid periods.
It's only when there is a huge amount of this coupled with water/coolant in your oil that you have evidence of a problem.
The best solution is to drive the vehicle for an hour or two regularly ...
The temparatures is normal,coolant temparature is 197F=91C so this is spot on what it should be.
Oil temparature is fine too,it is often a bit higher than the coolant temparature and this is normal.
The transmissiom fluid temparature is fine and it show your transmission is in good shape,105F=40C it is in the low range so no need to worry.
A tiny bit of ...
It is just a connector that is not plugged into anything. Presumably it is for an option that you don't have fitted to your car, hence it is not plugged into anything.
Why do you want to replace it? Do you think it has something to do with the ABS fault?