I'll answer #2:

It's extremely satisfying to be a part of people's journey to stack sats. Previously, my favorite product I had ever built was the trading feature at Unchained Capital. Helping people stack sats directly to cold storage with keys that they control.

Zaprite helps you do the same. Stack sats directly to a wallet of your choice. Often times that is directly to cold storage with keys you control. I wanted that for a decade before being able to build the products to encourage that behavior.