Venser + Conjurer's Closet

Assume I have a Venser, the Sojourner, Stonehorn Dignitary, and Conjurer's Closet in play. I use Venser's ability to blink the Stonehorn Dignitary. At the beginning of my end step, can I use Conjurer's Closet to flicker the Stonehorn Dignitary after it returns to the battlefield from Venser's delayed trigger? When do you have to choose a target for Conjurer's Closet? Do you choose a target when its ability enters the stack or do you choose a target upon resolution? (I believe Venser's 'return the creature' ability hits the stack at the same time as Conjurer's Closet's ability, so you can choose the order) If someone can post an official ruling I would greatly appreciate it!

Follow up question: I know Stonehorn Dignitary's ability stacks - as in you can have 2 enter the battlefield the same turn to have an opponent skip their next 2 combat phases. What if I play 3 of them on one turn (opponent skips next 3) and play another one on the next turn? Would they skip another combat phase after the original 3 were over?

Thanks in advance!