MNK secondary stats, also minimum Skill Speed?

I've been doing testing of my own on and off, but honestly I'd just like an answer. Is there an optimal Skill Speed? I notice just a few hundred SkSpd has a noticeable effect on the normal cooldown of combo skills, but much less with full GL, so I'm wondering where the importance lies. Getting three stacks of GL is easy when opening with RoW, so is it still worth it despite the reduced effect, or does its increase to auto attack damage make up for it? I assume auto attacks are still the MNK's largest, most consistent DPS output.

SS's effect on autoattacks isn't significant enough to make it the best stat. Or even especially good. It's not terrible like it is for some jobs (MCH and RDM, for example) but it's not great.

BiS sets taken from The Balance:
http://ffxiv.ariyala.com/18M7M - 2.06 - Eureka
http://ffxiv.ariyala.com/17BD8 - 2.06 - No Eureka
http://ffxiv.ariyala.com/18M7P - 2.05 - Eureka
http://ffxiv.ariyala.com/18M7Q - 2.04 - Eureka
http://ffxiv.ariyala.com/18M7S - 1.99 - Eureka

So there's a bit of flexibility there, and SS is generally valued somewhere around what Determination is -- that is, worse than Direct Hit and significantly worse than Crit.

The amount of sks I use for my monk is 1315-1320, which should make your GCD 2.35 secs. However, this is only if you are really tight with you GCD rotation.

Usually, the monk rotation, starting from Opo-Opo stance, is [DK, TS, Demolish, Boot, True, Snap], then repeat. However, with 2.35 GCD, if you start the rotation with GL3, your rotation can be [DK, TS, Demolish, Boot, True, Snap, Boot, TS, Snap, DK].

If your timing is spot on and you don't clip, the final Snap will get the DK buff. Your next DK and one AA won't get the buff, but it's fine since the main reason for doing so is for the two bootshines. Hitting a positional with that is a guaranteed critical hit, which consistently does more damage than DK even if it crits with the same potency (provided you hit its positional) over the course of a fight. What's more, since boot is a guaranteed crit, it's your highest, most consistent weaponskill that will passively gain chakra stacks. Also, if you get any kind of Arrow buff from an Ast, you can then fit it two True strikes within each TS buff (so your rotation will look like this: [DK, TS, Demo, boot, True, Snap, Boot, True, Snap, DK, TS, Demo]).

I do have to stress that you cannot clip even once during your GCD rotation, or else the coeurl move (either snap or demo) will not get the DK buff, meaning you cannot double weave oGCDs outside the opener (it also won't work if you have low ping). So if you're not confident in that, then it's better to just focus all your other stats on direct hit, then determination (Crit takes priority above everything though).