No way: I gave up trying to use the personal backups (and, indeed, I don't save them any more) even to upgrade from a version to another of the SAME image, because they never work: guess if it's possible to use them for two different images! They are simply useless.
No: save your bouquets by a software or by the OWIF itself and this is the easiest thing to do.
You want also, if you are an experienced user, to save the file "settings" in etc/enigma2 because it contains, among the other ones, the lines about your tuners' configuration (the ones starting by "config.Nims") but, if your system is not complex, it's a matter of one minute to reconfigure them.
About the plugins, it's much safer and clean to install them again.