There is an app called
iCab Mobile, it's a web browser that allows you to password it. It will also dump your cookies and history if you set it up to do so. As mentioned above, Opera or Firefox are also good choices. Don't have a shortcut on your desktop for the browser that you utilize for the hobby, and set it up to dump your history and cookies once it closes.
Open a new banking account and select paperless statements. Direct deposit a small amount of cash every time you get paid. If you get a raise, direct deposit that sum. You won't be able to hobby as often, but that is a good thing. It will minimize your exposure.
Password everything!