Hayward is an unrestricted free agent. Correct me if I'm wrong, but the Celtics can talk with him and wait until he makes his decision to start renouncing players. Regarding the players with player options, I don't expect those to be picked up anyway, so they can just be released regardless. I mean, Johnson looks like an old man now and Zeller barely got on the court. Why would we be scared of declining their options?
If Hayward agrees in principle (but not sign an actual, official contract) the Celtics can then renounce Olynyk and trade Smart or Crowder. I assume that this is something they have prepared for with teams that have cap space. It's not like they haven't thought of this beforehand.
Besides, we don't necessarily HAVE to sign any of those other free agents. If they're going to be overpaid, why bother? We can use the space to sign our own guys and/or give extensions to guys like Bradley or Thomas.
If the Celtics ARE interested in one of those other FAs and that player really wants to play for the Celtics, they should be willing to wait for Hayward to make his decision, but obviously there are no guarantees. Frankly, I don't think any of those guys are good signings, especially Olynyk. Though, it might be worth it just so that we could buy the jersey.