I have used it several times to sell iPads, used Switch games, and I think even a MacBook once.
1. It is unlikely. The difference between Swappa and eBay is that each transaction on Swappa is monitored by a human being, not a computer. They have a really good verification system for listings, and you should have no problems. JUST BEWARE of the excess fees. My advice is have some patience and just tell them to send you a check for the payment from the seller. When you start adding in auto deposits and digital transfers and stuff it knocks a BUNCH of money off of your profit and I feel like they purposely try to steer you toward those extra services. Stay away.
2. I have abandoned eBay and I will not use Craig's list. For gadgets and video game related stuff, I've been using Swappa for years.