I'll share. I use eBay's message system, generally speaking. This way, all communication is thru the system should any problems arise. Hopefully that won't happen, but from what I understand, it's easier for eBay to check into the situation this way. That could be totally wrong and I hope to not find out.
That being said, there absolutely are exceptions, like a boot buyer I had that was so excited to get them quickly. She was having problems clicking through the pay now button. We exchanged numerous emails and even with those problems, it was a most pleasant transaction. I shudder to think of confining our communications thru eBay's system for that one.
So I guess that makes my answer "c", a balance of both, while it's mostly "a", although "b" could also apply.
