In my opinion, your routers doesn't have roaming system.

I have hybrid optical 60 down / 10 up You can use 802.11n standard with this internet speed

Can I control Internet speeds like the c7 in the bandwith control settings Yes of course, you have bandwidth control function - http://www.tp-link.com/en/article/?faqid=557

but will this router support let's say 2 Xbox one and 2 laptops ? Yes of course. What kind of provider and internet speed do you have?

When you login by IP address is everything ok?

Another 2 questions: 1. What's prefer, connect the 4300 Direct to Archer C7, then connect Switch to 4300 ? Or Connect Switch direct to Archer C7, then connect 4300 to Switch? There is no difference...