1- Yes, you can make it editable but it is recommended that you first save the document on your computer and then edit it.
2- If there is an image in a document , you can run OCR on it but the ability to run OCR shouldn't be locked from the source.
Also there are other factors which in some cases doesn't allow the editing of the document .
3-Yes, Standard and Pro both will allow you to run the OCR on a document.
You can checkout these articles :
Thank you for reply, Shivam! If the sentences are image, can I still OCR and edit (fix type, for example)? (if there is no lock etc.)
Yes, you can but the end results depends upon the quality of the image or on quality of the scanned image.
Thank you so much. Your answer was helpful!