The .deb files will need to be for armel rather than x86, other than that you should be able to install any. You're likely to run into dependency issues though, as needed libraries may be missing. There should be no difference installing in red pill mode or via the command line.

As for recovery method - uninstalling is the simplest option. If you can't do that then reflashing (probably both firmware and eMMC) should sort anything out.

Frankly, I'd advise not doing this at all though - use the easy-deb-chroot (available through the repositories) instead. This'll give you Open Office anyway, and you should be able to easily install other common apps in the debian chroot, without risking side-effects.