1. Let me rewrite the first one as "How can I find what is using storage memory in Android?"

That has been kicked around for years so let's find that.

The top 3 hits are what I read.

2. The second issue appears to be the old USB doesn't connect issue. For that I pull out my good USB cable. many are junk. Also, many owners are completely lost as to USB drivers for phones. I like XDA Forums if the maker doesn't call out which USB driver to install.

That out of the way I cheat. I use Dropbox and ES File Explorer to sync without a cable.