Nowhere in what you quoted does it EVER state that a Free Action can be an Opportunity Action...
From just above my last quotation:
[PH1 p 169]Two action types—opportunity actions and immediate actions—require triggers. A trigger is an action, an event, or an effect that allows you to use a triggered action. (Some powers require a trigger but are free
actions or aren’t actions at all.)
Since a triggered free action is not an immediate action and does have a trigger, that makes it an opportunity action by a process of elimination. In fact, there are no other types of action that CAN be opportunity actions by this definition and not be an Immediate action. No Action can be an Opportunity *Action* if it has a trigger. (making the term Opportunity *Action* a bit misleading).
Nowhere in what you quoted does it EVER state that... there is a general rule for how many times a Triggered Action can be triggered.
Let me repeat:
PH1 said:
Once per Combatant’s Turn: You can take no more than one opportunity action on each other combatant’s turn. You can’t take an opportunity action on your own turn.
If we consider all triggered actions (and triggered nonactions) to be opportunity Actions, the limitation on 1/turn for triggered actions becomes clear.
An Opportunity Action is it very own type of action (just like Standard, Move, and Minor) and is incapable of being both a Free Action and an Opportunity Action...
The text I italicized is a misunderstanding on your part, and this is the major point where we differ. Immediate actions are their own type of action, and so are opportunity actions. Opportunity actions would the by elimination be all triggered actions that are not Immediate actions. An example of opportunity action is the opportunity attack. Obviously an opportunity action cannot be a standard, move, or minor action (as these are proactive actions without triggers), but it can be a free action or no action. In fact, there is nothing else it can be - there are no other types of actions left for themn to be. I did a search of the compendium and got no less than 29 hits on No Action and the word "trigger", 90 hits on Free actions and the word "trigger". Checking the results, i find that most of these are not just random mentions of the word trigger but actually reefer to triggered actions.
By my reading triggered actions include two subgroups: opportunity actions and immediate actions. By this reading, all actions with a trigger that are not immediate actions are opportunity actions. Opportunity attacks are a subgroup of opportunity actions; all other opportunity actions are either Free Actions or No Action. (Actually, later in the chapter, Immediate actions also seem to be Opportunity Actions, but lets not confuse matters further.)
My view is naturally enough that my interpretation is the simpler one that leads to the most reasonable result in the OPs question above and is closest to RAW. If my argument does not convince you, I think we have to agree to disagree. As long as you can get your game to work with another interpretation of opportunity action, its not really important what I think. What IS interesting is that the rules, even in the 4th editions, can be so unclear on so many points and would dread being the judge at a competitive event where these rules came to the test.