Dear members of this forum, and please make short answers as you can:
Do you belive in perfect or almost perfect IP spoofing?
Do you belive in total security of wpa.psk TKIP wireless networks?
My short answers are no and no.
No matter how a person spoofs an IP address, they still need to access the internet by way of a legitimate IP address. Given enough motivation to justify the expense and having access to the proper resources, their actions can be traced back to their specific point of access.
There is no way to provide absolute security in any wireless transmission. Anyone with a good packet sniffer that can monitor the transmissions long enough will eventually get the necessary information to actually view the data.
As posted, I'm with the others. There are extra steps that can be taken. Rotate the wifi secret (password, basically) every week, same idea on spoofing. If you do it, and then sit still, you're done. There's an old science fiction book series that said, "anything that science can invent, science can circumvent."