My 1password 7 filevault was kept in my Dropbox. Where is my filevault for 1password 8 kept?

Yes, if all of your data is on 1Password.com then you can remove the file in Dropbox. I recommend double checking to be sure. As they say It's a measure twice and cut once type of situation.

So, I can safely trash the copy that is still on Dropbox? I don't want to have copies of the file vault out there if they're moot.

@bobwayster

1Password 8 uses 1Password.com. 1Password 7 was the last version to support 3rd party sync types. The file itself is kept in the users Library folder.