1. Yes I do use it, and/or consider it's suggestions in order to either re craft my titles or leave them be.
2. I think it's an OUTSTANDING feature that this site gives.
3. Sorry, I really can't say for certain about changes in traffic, I now have too many hubs to pay close attention to all of them; and I only want to produce more hubs.
4. Really, this site gives you every single last thing to succeed, you'd have to have a personal tutour about hub creation to need get a more thorough and diverse opportunity to make money on the net than what this place is doing.