Is there any objection to script owners be able to remove comments on his scripts?

Also when removing a comment he could inform if it was a spam or not...

I disagree with this; script authors could then abuse this by removing negative comments or, in the case of a malicious script, comments warning other users of this. Spam comments are picked up by the admin pretty quickly as it is, so I think the flagging feature is sufficient.

there's a flag script feature, which is more trusty than comments...

Also my scripts spams take ages to be removed, if they are being removed, there's more than a week I flagged some spams and nothing til now...

I agree with ZNERP, but it would be good if I could delete my own posts and/or comments.
The reason for this is because I posted a comment on one of my scripts just to alert users that it was a very basic version but working, now I want to delete that comment. Is it possible?

Feedback #4651. Just vote for it. I agree with znerp, though.

I'd like to be able to edit my own posts sometimes to fix goofs. The ability to deleting and re-port would of course satisfy this.

Feedback #4676. It will be implemented.