Celtics face conundrum with restricted

Sully has averaged 7.3 defensive rebounds per 36 minutes in his career. Since his rookie year was his 2nd best year I went career and not just last 2-3 seasons. 

Horford is a career 7.0 def rebs per 36 mins guy in his career. But the last 3 seasons that has dropped to 6.1. 

Since Sully can't be relied on to play the 32 mins per game Horford is virtually guaranteed, I can't see there being much of an impact here. Sully deserves like 18 minutes on a contending team, even if he's in relatively good shape. Meaning the Celtics will be missing out on like 4 def boards a game from those 18 minutes while gaining 32 of Al Horford. Even if he only grabs boards at 75% of the rate Sully does in those 18 mins he is also replacing 14 minutes that another bench type player (Zeller, Olynyk, Lee) was given last year. The overall impact of that is huge. 

The Celtics played really well in lineups that had a healthy Olynyk in them shooting 40% from 3 and whenever Amir was on the court, although he can't be relied on for much more than 18-22 very efficient and impactful minutes per game. So if the C's have 32 mins of Horford, 24 of Olynyk and 20 of Amir Johnson, you still have 20 minutes left and should really bring in a very good shot-blocker like Ezeli, b/c that is what the rest of the frontcourt lacks. They have two great shooters, two great team defenders, two average to good shot-blockers and one average team defender, but you'd need to add one more guy who is very good at something. Ezeli should be that guy. 

Festus btw averages owns very good marks 7.3 def rebs per game and 2.7 blocks per 36 min #'s from last season. Hid PER is around 17 and he has great defensive numbers in small minutes (14.1 per game). Give him 12-14 million per year and 18-22 minutes per game this year, followed by more when Amir leaves, and see what happens.

Is there a time frame where a restricted free agent either has to accept the qualifying offer? It does not seem that any team would want to carry the player's cap hit if he is not going to play for that team.

I could see Sullinger back in a Cs uniform for one year at the qualifying offer he was tended as his contract would be very inexpensive for the team while providing some experienced depth. It would give this guy a chance to get himself together physically going into free agency again next summer.