Twink Myrrh, sure. (e.g. lvl. 20 Myrrh to 20/12 averages, doesn't really take damage unless you hit weakness or ignore defense.)
I'm fine with a combination of 2 & 3. Not sure how many interesting twinks of FE there are, "overlevelled" is kind of all a lot of characters have as an option which is boring except in a few cases. Like Myrrh, actually. FE9 / FE10 have more options, at least, thanks to the skill system.
I will say that any non-FE characters for fun should ideally be from roughly comparable systems - e.g. FFT or WAXF.