Four live connections, and a deliberate refusal. KitSlate connects where a connection is genuinely better, and exchanges files where a connection would be a liability — and it says which is which rather than implying more than it does.

Each company connects its own Google account, so a studio running two companies out of two Gmail accounts keeps them separate. Every save writes into that company’s chosen calendar within seconds.
Stripe handles card payments on invoices, and every document KitSlate sends leaves with your company on the letterhead and replies coming back to you — not to KitSlate.
KitSlate has no connection to any of them. It reads and writes their formats — you export from them and drop the file in, and you export a CSV to take back. Nothing is fetched and nothing is sent.
No, and it will not pretend to. It reads and writes their file formats — you export from them and import here, and export a CSV to take back. Nothing is fetched from them and nothing is sent to them.
Yes. The connection belongs to the company, not to the workspace, so each connects its own account and disconnecting one leaves the others untouched.
No. The invoice carries a pay link and a QR code that open Stripe’s own payment page.
Documents send with your company on the letterhead and your reply address, so a reply comes back to you rather than to KitSlate.
The sandbox shows the calendar, the documents and the money side without any account to connect.