If I have a two rules that trigger from the same event and one rule at order 50, and the other rule at order 60 - will the rule at order 60 wait for the rule at order 50 to finish before executing if we have "run rule components in sequence" enabled?
We are seeing some weird timing stuff going on which would suggest it doesn't wait, but I would like to know for certain.
No, the order 60 rule will not wait for the order 50 rule to finish firing first.
Strictly speaking, it is the rule's events that are ordered. So you could have a Click event with order 50 and a History Change event with order 60 in the same rule.
You can think of Launch organising the rules events into a list, sorted by the order. Then it just runs them from first to last, such that the order 60 one is guaranteed to start running after the order 50 one has started. But no timing condition is used (as far as I know).