Is it worth taking it in? Absolutely! Apple have legendary customer service and will likely fix things they have absolutely no legal obligation to fix.
The power cord is absolutely covered. Apple will replace it free of charge under your warranty. As for the weathered keyboard key, they may likely do the same as that shouldn't be happening and a replacement key (which they will likely have a plentiful supply of in the back) costs next to nothing and is trivial to swap.
As for the scuffing on the case, they may shy away from that as that is a) a considerable amount of work to do and b) not cheap. But press them and you'll find that they may just acquiesce. The unit should after all retain its coating and they may tell you it's a "one time cosmetic replacement," but will still do the servicing.
I have personally had them replace my iPhone even though I couldn't reproduce the problem I had reported. My friend had his replaced, free of charge, after he dropped it and admitted to such when bringing it in (he is not alone here, as I have had other friends receive the same treatment). They also overnighted a new battery when my MacBook Pro was 6 months out of warranty!
I always encourage people to make use of their warranty. Apple's customer service is bar none the best in the world. Truly. They will make you feel like you own part of the company. I cannot express here how good it really is.
While you may not find precedent for them to fix any of those issues, you'll soon find that you won't need to. Apple works to make you happy, and not just to meet some legal requirement.
I work at an Apple Authorized Service Provider, and the fact that they won't tell you what they did means it was probably just an SMC reset that took two seconds. From Apple Support:
The System Management Controller (SMC) is responsible for many
low-level functions on Intel-based Macs. These functions include:
- Responding to presses of the power button
I'm guessing they didn't tell you this because all it takes to reset the SMC is holding down 3 keys and the power button at the same time while plugged in, and you'd possibly argue about having to pay them. It seems pretty shady of them, because we have machines come in needing a simple SMC reset all the time, and most of the time we waive labor charges, but for them to not even tell you that that's what they did doesn't make a lot of sense.
Best Answer
This can be fixed with an application of Super Glue or other adhesive for metals.
First, clean it with acetone - use a cotton swab (like a Q-Tip) to ensure that the metal is clean. This will help the adhesive bond properly
Using a small amount of adhesive that is made for bonding metals like Super Glue, place it around the edges of the part to be repaired. Hold for at least a minute (the set time for the adhesive) and you should be good. For best results, allow to cure for an hour before use. You should be good to go