Payment processor option

Hi. I own a street food caravan since 2014.

Acceptance of payments has evolved a lot, our customers ask us to pay by card.
We are not sure if we should go by Square-up, PayPal or any other type.

The desire to implement EMV especially without contact. My questions are.

1) How many non-contact payments can be made before customers are asked to enter the PIN number. This is a problem since we want to maintain a fast flow.

2) How to handle friendly fraud.

3) Regarding the above, the payment processor is the most "friendly" when it comes to chargebacks. We read horror stories where companies had ALL their funds blocked by 1 chargeback and went bankrupt because they could not keep up.