We should certainly do it. We have to hit the floor at least. so using it to get some assets would be ideal.
That said, I don't think it would be very easy to get great deals. It's not like we are the only ones with cap space. For example (all data from hoopshype), Sixers, if they don't pick any team options, have a salary of just over 35M this year, and only 8 players on the roster. Even after adding their picks, they will have tons of space, and several open roster spots in which to slot these assets.
By contrast, our salary next year (assuming we buy out Afflalo, don't make a qualifying offer to Ben, Rudy sticks to his plan of opting out, and Galloway comes back) is in the region of 45M, and we'll have 9 spots committed. Once we add our 3 rooks and Bogdan, we'll have just two roster spots. If we take back a back a bad contract, we can take only one draft pick/prospect. And this assumes that we'll have only rookie PG on the roster.
I understand other scenarios (trading Afflalo, but that doesn't save us a roster spot. Plus, if teams can trade to a team willing to absorb a bad contract completely, why will they bother trading for him). Similarly, we may be able to open spots by doing 2/3 for 1 trades, etc. However, till such times, we'll have challenges with both available roster spots, as well as other teams with cap space. We might want to focus more on future assets, than current.
I think we should not take contracts more than 2 years in length, unless it's for someone who really fills some need. We will be bad this year, and that's okay. We don't have our 2019 pick though. Some of the kids would have hopefully proven themselves by then. We'll have a high pick in 2018. All these can entice a decent FA, who sees long term potential with the team. Lots of assumptions of course, but mainly wanted to highlight that roster spots will also be a matter of concern for us.