2 questions about open ports in comodo.

Hi, here are my questions:

First:
Is it correct that only the programs that are allowed internet access in the application monitor, will be able to use an open port from the network monitor?

Second:
Would it be wrong just to make a rule allowing all ports in/out? (on TCP/UDP)
If no apps. are using the ports, all of them are stealth ?
Other firewalls opens the port when you accept incoming connection to the server once.
Creating this rule in comodo would make comodo act the same way?
Is that a bad idea?