You are understanding it correctly. What one does to create a block depends on the Proof of Stake algorithm used.
Block creation time can be controlled the same way as in Bitcoin. Through difficulty adjustment etc.
For code examples you can look at the source code of Proof of Stake coins at their github. A simple google search will give you a list.
So, the chosen "miner" have to perform proof of work also?
What if a node doesn't find a solution to PoW? or if he delays a lot more than the estimated block creation time?
Then what is so revolutionary at PoS coins if they depend on Proof of Work? it doesn't make any sense for me.