I would not use Square, period. Since they are anti-gun why give them any money?

Here is my take on plastic, which I use a lot. I have run a small one man service business for 36 years.... about 30+ years ago a business consultant said I needed to accept credit cards so that people could pay me with them on big jobs... and so I did sign up... had to carry one of those mechanical swiper machines around with me... after about two or three years I got a letter from the bank saying that I could not process cards anymore because I had only done two in the last year.... So, since then I have not accepted plastic and you know what? It has not been a problem.. On the rare occasion that's all the folk have, I just bill them. And have never been stiffed.
Every once and a while I go to a vacation / weekend home probably owned by one of the folks who are making that 2-3% off these cards.... these homes usually run in the 2-5 million dollar range. It is all a legal scam.

I don’t think you can charge a fee for credit cards. You’ll have to bump the price of your service/product a few bucks to counter the credit card processing fees. Of course, let them know that a cash deal gets them a 2% discount if you want to go that route.