Hello taskellusaf. I have read your post and understand your concern with hiding your signature when sending an email. You will want to go to Email Settings, Compose Options then Erase Signature.
Go to G-mail website on PC, click "settings" in top right, then "accounts and import", look in "send mail as" box and click on "edit info". Click on the dot next to the empty box, and then you will have to put something in the text box. I put an underscore line. Click "Save, and you're done. Hope this helps!