Agree with the discounts. It's what attracted me to try spending in Bitcoin (a small discount or cashback or similar in return for the additional inconvenience). It's also what attracted my very first Bitcoin paying clients -- often, especially on larger invoices, 5% off can be quite a savings, especially over long-term contracts.
Don't ask your customers to use third parties that can ask for kyc.
Yep. Terrible idea. And that KYC can get both parties in trouble with frozen accounts. As a consumer/customer I truly appreciate when a website doesn't force me to use Bitpay, for example. It makes my life much harder, forces me to overpay fees and estimate a high amount, forces me to disable RBF (among many other inconveniences!).