I’m a senior engineer at Startpage, and I can personally confirm all of the above. Our system is implemented in such a way that we never store a user's search query, IP address, or any other personally identifying information, and that will never change. If anyone is interested, I can answer specific questions about technical details.
Not necessarily. Betablockers can treat symptoms of anxiety resulting from activation of the sympathetic nervous system by blocking the action of adrenaline on adrenergic beta receptors. They may also have psychoactive effects (for example, propanolol appears to have some effect on memory consolidation [0]) but it's the inhibition of the body's "fight or flight" response that is helpful in treating performance anxiety.
This functionality actually already exists. Artists can add a purchase link to the store of their choosing, and it will appear right next to the "Share" button.