We'll just have to agree to disagree on Whiteside's offense. I don't think Whiteside has a good offensive game at this point. He has potential to be better as you stated, but right now he's better suited to be a lob and dunk player. In double team situations I agree he has a strong upside. They should actually try to get him to re-post after initially passing out of the double team. His passing is terrible tho. Which is another problem.
You may be onto something in terms of offensive flow affecting Whiteside more than other player. When the ball moves he should be able to get easier buckets. He struggles if you continually go to him for points in the post especially in low clock situations.
As for free throws, Whiteside at 50.6% is shooting a lower % than Dwight Howard. One of the worst free throw shooters in the league. If he's gonna play down the stretch in the 4th he has to bring that up.
I actually liked the Heat's ball movement against Charlotte and Boston. They had 25/23 assist, but sill lost those games.
They are at the bottom overall in terms of assist per game only averaging 19 a game. This is where Spo has to figure things out. They are actually down from last season...
Out of the 9 teams the Heat have lost to, 4 of them are top 15 in 3 point shooting%. Cleveland, Indiana, Hornets, and Wizards. 7 of those teams have stretch 4's who could shoot. So whatever Spo does, he has to get Whiteside in positions to defend on the perimeter, and get the team the share the ball more. The ball can not stick. The Heat have looked their best when there is balance scoring the ball.
P.S.
After looking at the stats, the Heat are actually not doing that bad with turnovers. They are the 2nd best teams in terms of total turnovers thus far this season with 14 per game... better than the Warriors. I guess they just have been sloppy as of late averaging 17 TO's per game. Whiteside had 6 against Charlotte and Dragic had 5 against Indiana.