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.
Coinbase can do it all. You can buy from them and send BTC. Don't think theres anything else you need... Dunno what the pgp key is or what its use for, but someone on here will give you an answer. Sounds to me as if you're god to go mate! :)→