1) Don't use Google for search, use StartPage. Especially if you want to keep search results confidential.
2) Enjoy the fact that Google synchronises data between all your devices and that you can - in the event that one device is u/s - go and buy another one which is immediately able to access everything you've previously done. If you don't like this, see (1) above.
3) My HTC Android threw a wobbly yesterday and it took less than five minutes to reload back to where I was beforehand.
4) I have several google a/c's and they have never cross-fertilised.
Google isn't scary unless you use it without understanding the philosophy of their structure.