Can i trade in phone with semi messed up charging port

Nobody here knows what’s considered acceptable problems or damage.

Try it. See what you get offered once your device is evaluated, if it differs.

AFAIK, you can reject a counter-offer, and elect to receive the iPhone with a not-entirely-working-Lightning-port back.

No quite sure, Apple has no set criteria for device damages they accept. You should try filling out the form and mailing in the device and wait for a response from Apple or take it to your nearest Apple Store.

To trade-in via mail click here, to find your nearest Apple Store click here.

I hope this helps you with your question.