Kill bit related questions...

Like so many things the answer to this is Yes and No. Since a program (SpywareBlaster) sets the kill-bits in the registry, another program could remove them. So, a spyware program could certainly do that.

However, that spyware program must first be run in order to remove the protections. If that program itself is an ActiveX control, that would run like any other spyware ActiveX control from a website using the ActiveX permissions set in IE, then SpywareBlaster could just as easily prevent it from running by simply adding its kill-bit to the registry.

If the spyware program can't run, it can't remove SpywareBlaster's protections. Of course there are many other techniques for attacking systems and weakening protections, and many of these move from the realm of spyware into things like Trojans. But again, if such programs appear out in the wild then products like anti-virus and anti-trojan would target them and block them.

The way ActiveX is linked into the Windows OS, the kill-bit capability will always be able to stop specific controls without a problem.

All the kill-bits are added to the registry when you tell SpywareBlaster to protect the checked items, so yes it does technically increase the size of the registry. However, the size is not what I would call significant. Given how compact these keys would be once added to the registry, the size change isn't worth mentioning.