Can I connect more than one Salesforce org? Not in this version: each tenant has a single Salesforce connection at a time (the “principal” one, Connections tab).
Can I use Production and Sandbox separately? Not in this version: the connection uses the My Domain URL you pasted (section 4), which points to ONE single environment — Production or a specific Sandbox. To test against a Sandbox first, create your External Client App there and use that Sandbox’s My Domain URL; to move to Production, repeat the connection with your real org’s data.
The credentials stopped working — what message will I see?
If the credentials are invalid, you’ll see “The token isn’t valid; check it and try again” (code INTEGRATION_CREDENTIAL_INVALID). Check the Consumer Key, the Consumer Secret and that the integration user (section 3) is still active, and repeat section 4.
Salesforce isn’t responding — what message will I see?
If Salesforce has a temporary incident, you’ll see “The provider isn’t available right now. Try again later” (code INTEGRATION_PROVIDER_UNAVAILABLE).
My Salesforce plan doesn’t have the API — what happens? Without REST API access (section 2), the verification in section 4 will always fail, no matter what data you paste. Check with your Salesforce admin whether your plan includes the API add-on, or use a Developer Edition org to test.
Can the agent delete leads in Salesforce? No. The agent’s tools (section 7) only search, look up, create and update — they never delete anything in your Salesforce.