free up space on iphone
There are a few ways you can clear up space on iOS. First of all, there are apps on the iTunes Store that clear up junk on your disk. I used one of these and it opened up 4GB without deleting anything that I noticed. You can also delete browsing data by going into Settings > Safari > Advanced > Website Data. Scroll down to the bottom and click 'Remove all Website Data'. You can also just delete data. There are some others, but there are just a few.

I know this doesn't answer all of your questions but hopefully, it helps some.