I don' really see any major red flags here. Tell them they can pay with a credit card through Paypal or use Direct Checkout.
Many buyers are first timers to Etsy...can't ding them just for that.
major red flags to look out for:
- want to use a 3rd party shipping company
- are away at sea
- don't mention items they want, ask questions listed in the listing (i.e., what is the condition of the "item", how much is the "item"?)
- want you to communicate only at their email address (if combined with some of the other items listed above.....but sometimes this is OK as many customers would rather communicate via email)
- want to overpay so you can send them a refund for the overage
- want to send certified check