I've been on the receiving end of a Talon Rolled TIE Attack Squadron multiple times, with the only Roll in their deck coming from Defense Protocol. Two cards combos can't be relied upon, but they're not all that rare either, and will see play in a decent number of games.
And I'm curious, by your definition, are zero cost cards "free"? Things like Force Choke cost you one card. Is an extra card really all that much to ask to remove any single character your opponent has out?
But in general, yes, I agree that Bounty Collection could have been much better (and I wish it were). All the capture effects in Boba's set are overly constrained.
I think there's a difference between a combo that requires a card on the board (possibly from a previous turn) and requiring two cards in your hand (Caputred + Bounty Collection). If you use the two cards from your hand you are likely down to 4 cards, if you then take advantage of that even by spending the resources you are likely down to 1-2 cards making it difficult to win an edge battle.
I'm not saying two card combos are impossible or should be ignored but if you are judging the value of a card off of it's two card combo alone you are ignoring the negative effects that come with carrying the card in your hand (or deck).
In this example carrying Captured and Bounty Collection requires two different objectives, you are also probably going to include 2 of each to get the combo off, so that is 40% of your deck you've committed to this two card combo. When you look at the other capture from play cards the results become pretty underwhelming. Dengar's set? I guess their is Bossk but then you are putting in 4-6 objectives with no resources seems like a tough call. If the card pool expands to give a lot more in play capture I think this event will be great right now it's just not a worthwhile combo.
In the other example both Talon Roll and Tie Attack Squadron are in the same objective set. There's also an additional fighter to use with Tie attack squadron again in that same objective set. You now have 2-3 cards that can combo pretty well together by including one objective. The effect of the Tie Attack Squadron combo is also likely much greater, two targeted strikes (likely 2 dead units), 4 objective damage. All for the cost of 0 using just Talon roll leaving 5 cards in your hand to win edge play additional etc.
As for the zero cost cards, yes I think they have a cost. The cost is one card out of your hand. With the edge battle being such a big part of this game force orbs are something to be valued as well. Imagine if force choke read "Action: Discard a card to deal one damage to target Character or Creature." The card would be much less powerful because of that additional cost.