When a user is blocked, that is just from pming you. That does NO good for posts. The user that is blocked should be blocked from posting in blockees threads also

In first:
How To Post A Site Suggestion

In second, no.
The inability to post in a few subforums is because of the warn. The blocked function is perfect how it is. People should be able to post normally outside the limitations who are from the warns. And if they spam/flam you have the possibility to report their post, and the Moderators take care of it.
Not going to happen.

So how would you defend yourself if someone made a s/a topic, accused you and also blocked you?

I also agree with what Nico said,

No from me.