Should I sell my old phone?

I had a iPhone 6s rose gold 128gb and now got the new iPhone 8 plus and not sure if I should sell the 6s or keep for back up? And if I sell. How much for?

Game progress not showing?

I had my old iPhone where I have been playing the candy crush saga, and saved my level with Facebook. Now I have a new iPhone and after reconnecting to Facebook from the new phone, the progress says I'm on level 216 but in the map page, it doesn't show more than 35 levels whereas on my profile it says I'm on level 10 and completed 216 levels, but on the map it shows only up to level 35z please help.

Can I ask for a replacement iphone 8 if mine is defective?

I recently just got a iphone 8 plus from kijiji. But i've noticed that my battery drains quickly on it, compared to my iphone 7 plus. The 8 plus is supposed to have better battery life and its also newer, so this doesn't make sense. I'm wondering if I can go to a local apple store and have them give me a replacement. I don't have a receipt or extended warranty. But i heard that all Iphones come with 90 day warranty, and since the iphone 8 just came out, does this mean I can ask for a replacement without a receipt?

IPhone X Limited Supply on a plan?

I'm looking to get an iPhone X on a plan with Telus and was hoping to hold off another month. I have come to understand it is limited supply, but will I be able to get it on a plan still next month? Or is it only available on a plan now with preorder?

IPhone 7+ vs IPhone 8?

IPhone 7+ vs IPhone 8? - 1

Added (1). Right now, I have an iPhone 6 and want to upgrade. Is it worth spending more money to get a regular iPhone 8, or should I just go with a 7+ and why?

How to change my backup for my new iPhone?

So today, I went in to Apple and exhanged my busted up phone for a new version of it. I booted up the phone and I got two options, a back up for 2/2/17 and 9/28/17so I pressed the 9/28/17 but it updated to the 2/2/17? But I went to iCloud> manage storage> back up and the 9/28 one is there, and is different… How do I access this backup? More of my old photos are on that one obviously.