1) No comment. We do not condone, support or assist in the production of malicious code in any way, form or manner. This is a professional site for professional developers. And explaining such things would aid the malicious-but-stupid more than the victims.
2) No. You cannot stop messages being delivered to your router via your IP unless you disconnect the router from the internet. Think about it: until the router receives the packet, it doesn't know where the packet comes from! :laugh:
3) Dunno - probably would depend on the specific router.
3.1) Dunno - again it will probably depend on teh specific router.
Try reading up on DDOS, there is a summary here:
Mitigating DDOS attacks[
^]
And
Google[
^] can help as well.