Arrow - Spoilers galore

I think I'm OK with the Monitor angle, but...Felicity was told it's a one way ticket, then how does she get back? And why not Arrow? It's just weird. Unless the Monitor placed conditions on her returning to Earth. She's in the flash forward scenes. How did she get there?

Too many questions, lol.
He says, "Where I am taking you, there is no return." Then flashforward Felicity says, "I've been waiting a long time to see him. I'm ready.."
Oliver doesn't die. He just got forced into another part of the multiverse. Calling it now.