we do not share your data with anyone and there are many ways to control the visibility and storage life of your data here.
but the internet is a public space and you should always assume your data could be compromised.
be smart with your password, use tor or a vpn, and use pgp for sensitive communications.
1 yes. extra funds are never a bad idea till you get a handle on things, lots of people have watched these extra coins grow too.
3 the btc price is good for a few hours while you pay→