The problem with sticking an external hard drive from one system into another system is that the User/Group IDs on the external hard drive don't match the ones in the /etc/ directories of the computer you're connecting to, resulting in files belonging to some very strange users and groups. That's why, when you plug the hard drive in and access it, you get some really, really weird locking errors. However, when you chroot, as you did, you bypass that by using the /etc/ directory on the external hard drive. That's why you have to chroot if you want to recover stuff easily.

I've never done this, however it should be possible to run a graphical browser app using chroot with some option (followed by the name of the app), as I can remember seeing this in the man pages. Please check the man page of chroot for more details. Note: you may still have screwed up user/group IDs on the destination hard drive after a copy. The only real solution to that is to become root (or sudo) and chown the files to something the graphical interfaces can handle and then carry on.