You can play all roles, it's only for newest coil that is preferable to have top end gear, everything else can be done with previous tier gear. Just because you are gearing up a DPS job, does not mean you have to run dungeons on that job! I main MNK for coil, I run DF as either tank, healer or DPS and initially use the tomes to gear up MNK, then tank, then healer. But you can still gear up your other roles, presently, with soldiery which isnt capped. 110 is enough for all content, including final coil.

So whats the problem?