Testing steps are as follows:-
Enabled Captcha Module.
Enabled node_edit_for...

Testing steps are as follows:-

1. Enabled Captcha Module.
2. Enabled node_edit_form captcha point.
3. Changed captcha settings accordingly.
4. Created a new anonymous user.
5. Added edit and add node permission to it.
6. Tried creating a new node and tried editing the node from this particular user.
7. If i put wrong captcha, it gives error to me.
8. Everything works as expected.

Attaching screenshot for the captcha here too. #7 Patch works as expected. Issuing RTBC to this.

Thanks!