Adapting a sourdough recipe to poolish (with new question 12/19)

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I prefer to use only enough yeast to do the job and avoid usuing more than necessary.  I typically use about 1% yeast for my cinammon rolls.  Works just fine. 

Without knowing the formula you used it's difficult to know exactly why your dough was not firmer, except that it's obviously a factor of hydration.  If you didn't adjust your final dough for the 100% hydration in the poolish you would clearly have a very slack dough.  My cinnamon rolls are typically 52 - 59% hydration, and if I use a poolish I have to factor it's level of hydration into the formula to avoid a slack dough.