[eschwartz]

1. It is, unless the previous owner jailbroke, installed hacks, and then uninstalled the jailbreak while leaving the hacks. Theoretically possible, but doubtful.
2. Reset To Factory Defaults will do Exactly What It Says On The Tin.
3. Uninstall each hack, factory resets do not affect installed hacks -- well, they do wipe the userstore, which is its own problem (settings and binaries are stored there ).
4. It won't be bricked, but see #3.
5. Yes, Kubrick is an invaluable resource.
6. No, other character sets should be unaffected or else have their own font overrides applied.