1. Yes it is F2P, but you can have a premium membership if you want some better benefits (better queue times, experience boosters, shop discounts, etc). I believe it is around 12 - 15 monthly.
2. A gaming PC is recommended. But you can try to play on low settings.
3. No you are not harassed, plus there is no healers so you shouldn't have to worry about that. :)
4. I don't believe it is pay to win. Atm I do recommend premium to beat the queue times and login quicker, but besides that, you should be fine.
5. Yes the controls are great imo, the battle system is pretty different from XIV. But at the same time its not I guess. The abilities still have cooldowns like xiv does, but the way you fight is a bit different. Some attacks do not have cool downs, so you have a lot of hack and slash.
6. Yes there are emotes. You can dance and stuff too.
Hope you enjoy the game! :)