Yes, that is correct - you must roll once for each condition marker to remove it.
Daze: Yes, each individual attack is rolled for - to see if it misses. This is normally done at the end of the Declare Attack Step (before the Avoid Attack Step, and before Defenses have to be used). However, if there is no Declare Attack step, then the rolls are made as soon as the attack starts.
With Triplestrike, you normally skip the declare Attack step on the 2nd and 3rd strike (because the target was already declared once with the first strike). But, you still have to roll to miss for each attack.
We are releasing a FAQ soon, which will cover this particular topic with Daze, as well as a few others. it is being written by our rules guru Alex Mont and should be up sometime next week.
Hope this helps!