An additional benefit of isolating the account is it would help to limit damage if it gets frozen and cancelled. There's a non-zero chance your bot-controlled account gets flagged for "unusual activity".
I can appreciate there's also very high risk in giving your bot access to services like email, but I can at least see the high upside to thrillseeking Claw users. Creating a separate, dedicated, mail account would ruin many automation use cases. It matters when a contact receives an email from an account they've never seen before. In contrast, Amazon will happily accept money from a new bank account as long as it can go through the verification process. Bank accounts are basically fungible commodities, can easily be switched as long as you have a mechanism to keep working capital available.
Also, at best, you can only add to the system prompt to require confirmation for every purchase. This leaves the door wide open for prompt injection attacks that are everywhere and cannot be complete defended against. The only option is to update the system prompt based on the latest injection techniques. I go back to the case where known, supposedly solved, injection techniques were re-opened by just posing the same attack as a poem.