Does dead yeast result in a stickier dough?
No, the dead yeast (if it was dead at all) has nothing to do with the stickiness. 

Your dough has 87.5% hydration, which is unusually high. It also uses, for some unclear reason, pastry flour, so it will behave like much higher hydration. 

The stickiness is absolutely to be expected with this recipe. If you have never done high hydration doughs, maybe you want to start in a more gradual way, maybe something like 80% with bread or at least AP flour, and and when you are OK with this go on to work with wetter recipes. Also see What can I do to keep high hydration dough from sticking to my hands? for how to become a bit more comfortable working with sticky dough. 



If you don't know how to arrive at the number: 
1.75 cups of water is 420 g 
4 cups of flour is 480 g 
420 is 87.5% of 480, so your hydration is 87.5% 

You can repeat the calculation for other bread recipes.