As an older father, a new guitar can be like a new child........& you don't want to send the baby back, however we must understand the commercials of your purchase
1. that hairline crack is in the Poyurathane coating ....shouldn't be there, but is not relative to any slab construction of the body....you could consider it as a childs birth mark and accept it as such.....do not attempt to do anything with it
2. the rise & fall of the potentiometer knob is not acceptable......if the knob scraping is not the cause, the rotary shoe within the pot is the cause.......I have not heard of a potentiometer with a rising spindle, unless it were a Push/Pull variant ..and a standard [quality] pot be replaced for less than $10.00 US
3. So you have a choice.........does the guitar sound as a real Tele should sound?.......do you find the action comfortable to use?
4. Check your Terms & Conditions of Sale........if the Terms were free to return the guitar to Amazon, I would e-mail document the issues absolutely and clearly with Amazon & ask for a confirmation of their offer of a resolution
5. If the Terms state you are responsible for the safe return of a product to Amazon may include exorbitant freight costs to comply with the T&C of your purchase
6. If the latter is the case, you may be responsible for a $50 + return freight costs to comply with their requirements ......you cannot claim these costs back
After confirmation of communication, if the return costs were at Amazons responsibility, I would return the guitar
If 3. 5. & 6. are your case, install a replacement quality pot, keep & love the child.....
Sorry, Mr Rational.
Changed my vote.