question about support; if someone purchasing their product new from eBay instead of through dji, would that compromise the support at all?

Hi there, it is recommended to purchase the DJI products from official channels, DJI official online store or DJI authorized dealer's store. Thank you for your support!

No it will NOT affect support, I recommend you buy from an authorized dji seller, there are a few that sell on eBay. If you buy used you should get any warranty that remains, if any?

I bought through eBay, no issues