OK for some more down-to-earth piece of info, i'll correct a few things:
_ Higher level of Resta and MST willl not increase resta's radius.
_Battle Fos do not have to change their spell customization all the time. I personally have, with my fonewm, RA techs on the 3-buttons palette withough ctrl, SI techs with ctrl, grants on 9, megid on 0, occasional gifoi spamming from the F3 shortcut menu which does perfectly. The only moments when i change (and which are rather optional) are before barba ray and n-vh gol dragon for gizonde instead of razonde.
_Standing still is nothing great, even past the 150'.
_damage cancel is nothing,seriously. Even while playig with other advanced players, it does not "always" slow a team down.
_Something you told me in-game: that enemies' recoil from your spells depend on the damage you inflict to them. This is absolutely not true!
Now things you haven't talked about:
_Being immune makes a better support FO. How will the white mage unparalyse others if he is paralysed? Equip cure/para; freeze; shock; confuse units.
Def mats on this server. As the max for DFP has been raised by 100 (same for MST, less importantly), and given this can be made even more profitable with high deband, we can as well take advantage of it. I say use 50 more def mats for an elf FO than you would on the normal PSOBB game to have those supplementary 100 points in DFP., disdaining the other stats than DFP and MST. You'll do perfectly well if you're an elf FO.
_Rythm breaking? Far more considerable to me than damage cancelling. It is, on the side of the FO, the disturbance in the rythm with which he makes monsters have some recoil with say rafoie created by his support spells (which do nothing to make enemies have recoil), thus letting the enemies time to act -noticeably dangerous against gorans and ill-gills- ; and, on the side of the team, the disturbance in said recoil created by them attacking the enemies. But I won't personally tell them about it, as they have fun the way they want, mm?
_The elemaental staves to increase damage of simple attack spells by 40% each (namely adaman, laconium and zumiuran) are very useful against bosses.
And that's pretty much all. I know it's confusing about the rythm breaking part, but be a battle FO and you'll see.