I want to create a Google Scholar profile. As far as I can tell, such profiles are not transferable from email address to email address. Should I use my personal email (Gmail) account, which I will hopefully have for the rest of my life? Or should I use my university email, which is actually hosted and maintained by Google? I am a post-doc and will be at my university for the foreseeable future -- probably for a few years, but not forever.
Your personal account. You will then have the option to add and verify an institutional e-mail to it, inside Google Scholar. This adds a text "verified e-mail on myuniversity.com" in your profile.
Not everything in our future is foreseeable, even for those with tenure, and universities are particularly eager to deactivate old institutional addresses, for no good reason in my view.