Unfortunately, most of your "advice" is wrong. Especially 1, 2, 3, and 4. And none of them deal with the real issue.
1. Closing out apps is a bad idea. See: http://www.howtogeek.com/204552/no-closing-background-apps-on-your-iphone-or-ipa d-wont-make-it-faster/
2. This is partially useful, but has nothing to do with the OP's problem.
3. Nonsense. There is no benefit to this, and again, it has nothing to do with the OP's problem.
4. Deleting apps you don't use provides no benefit at all, other than to free up storage if you are short. If they aren't being used they won't do any harm. I have 280 apps on my iPhone, and use about 20 regularly. The rest just sit there, doing nothing and doing no harm.