Can 1Password for Safari window be resized? Or allow items to be opened in new window?

I believe the browser extension is a separate app that you download from the Mac App Store. As such, all updates are managed by the App Store. If you haven't used (or are unfamiliar with) the Mac App Store, there's probably an icon in your Dock for it, or if not, you can access it from the Apple Menu -> App Store. In the App Store, on the left hand side, you'll see an item for "Updates." Click on that, and you'll see apps that updated recently, you'll probably see the 1Password Safari extension in that list of updates. You can also use the "Updates" section to manually update apps.