I don't like the 'React now and pay later'.
I would prefer 'You hold your attack in order to evaluate the situation. For each attack you forgo, you accumulate an extra reaction in reserve.'
We discussed that earlier in the thread. You are describing a credit model, versus existing debit model There are a few differences:
1) Credit model is overall less powerful, because it moves your actions to a lower initiative count, rather than higher.
2) Penalty for guessing poorly is much more severe in credit model. In debit model the player cannot actually lose any actions, even if he spends them suboptimally. In the credit model the player might forego his attacks, and then have no reactions to take. (EDIT: unless you mean that you can hold the reserve round-to-round for the duration of the combat. That alleviates concern #2, but I find it a bit less elegant that keeping everything within a round.)
3) Credit model requires the
player to accurately predict what will happen, which is vastly more complicated than anything any other class requires. Debit model is a simulation of the
character predicting what will happen, but the demands on the player are much lower.
Credit model could be interesting and rewarding to play, but my sense is that it's too complex/penalizing for 5e.
You can't accumulate more extra reaction than your intelligence modifier (min 1).
At level X, when you roll initiative you get an extra reaction.
The first version was sort of like this. I waffle on bringing it back. I go back and forth on how MAD the class should be.
But combining the old version with the new is compelling: "You can trade attacks for reactions 1:1, but no more than your Int modifier (min 1)."
What do others think of that? Make this class Int-dependent?