Stealth Ports question

Hello. I don’t entirely understand how the net works but I wanted to protect my computer and installed Comodo Firewall. In Comodo tutorial (from here: Firewall Setup for Maximum Security and Usability,Firewall Set up,Spyware Scan| Internet Security v6.3) it’s advisable to block all incoming connections (‘Stealth Ports’ link in Firewall Tasks). I just want to be sure: is it really okay? Doesn’t it interrupt proper working of some programs? For example, BitTorrent clients? Can stealthing my ports disturb p2p connection somehow? I thought it’s necessary for them to connect in both directions, as I do not only download but upload as well. Or I simply misunderstood something?
P.S. Sorry if I made grammatical mistakes. English isn’t my native language.

You might experience issues if you do this yes. I suggest using ‘alert incoming connections’ instead.

Alert incoming connections:

“You see a firewall alert every time there is a request for an incoming connection. The alert asks your permission on whether or not you wish the connection to proceed. This can be useful for applications such as Peer to Peer networking and Remote desktop applications that require port visibility in order to connect to your machine.”

See here as well:

Thanks for the replying. I’ll do as you recommend.