You're uninformed on DoTs, sadly, Sentinel. DoTs DO crit (heck Bards get a talent that procs on DOT crits), they DO snapshot, and the 3 second server tick merely means that in some situations you can get an -extra- tick, but you'll always get the 10 ticks for a 30 second fracture - if you apply it too early such that it doesnt tick on the 30 second point, you'll get the extra tick at the start. The only time the dot timer will affect the amount of ticks a dot gives is if the DoT length isnt a multiple of 3. But most are.

You can show that dots Snapshot because if you pop it with a cooldown up, right at the end of the cooldown, the DoT will continue to tick with the same strength it was applied, and indeed you wont be able to refresh the DoT until it's run out because your non-buffed DOT is viewed as inferior and wont overwrite it.

Skillspeed is the only thing that doesnt affect DoTs, and skillspeed is viewed as a poor stat anyway.