Just wanting to know before it comes out Will you be able to pay for better items etc?

You will not be able to buy any items or any kind of boost to xp or dmg, of any kind for real money.

It's a subscription based payment plan. You buy the game, you pay monthly.

There is a cash shop of sorts, but it provides only account based services (name changes etc) and -possibly- cosmetic items that may or not be craftable as well.

Only vanity or 'fun stuff' in the shop, nothing that gives a player an in game advantage.
So no it's not pay to win.