Quote Originally Posted by Shurrikhan View Post
Is that a constant need, though? How many consecutive GCDs, and how many GCD per minute on average, must they be spread away for?

Keep in mind that even a "Melee" DPS like NIN can technically spend ~6 GCDs out of melee at a time without losing damage due to its two charges of Ninjutsu, Ten-Chi-Jin, and Phantom Kamaitachi; the problem is merely whether the movement away can also sync up with Trick Attack, since they'd want to spend those ranged GCDs under TA. Additionally, one's mobility also decreases the time each way one must be out of melee range, since a teleport (a la Icarus, even) allows you to arrive for a given stack at the last moment.

Give the "melee healer" even just 3 GCDs per minute that can be used at range, bankable to 6 in a row, and some mobility, and it will do just fine in the vast majority of serious XIV content.
Many fights are designed around the healers spending extended periods at long range. If you can't heal out there, it's not viable.