lol.
No. Port forwarding cannot effect a router to a point of not working or not functioning correctly.
I don't know exactly what you dad thinks. But show him this.
Port forwarding can be compared to a house with doors.
The more doors you open, the more communication. (traffic)
Some programs use ports to communicate. By default, most routers have all ports blocked.
Opening all of your ports is commonly referred to as DMZ mode.
Blockland only requires ports 28000 and 28030 to be opened.
So, no. It doesn't do much. But allowing you to host.