Major Issues With Acrobat

1. When I save an Actobat document that has been emailed to me, it appears to be ok when opened from the email. When I save it, any mark-up text becomes symbols. I delete it. Go back to email and save it again and same thing happens. 

2. When we open an Acrobat document and are working on it, all the pages will sometimes go blank. Have tried waiting it out but the the content never comes back. Have to close without saving changes and reopen. At that point, the content comes back but you have lost the changes you had made previously.

3. Will be working on a document, making occasional saves when all of a sudden I get a "Bad File Handle" when I try to save. After that, I can save no more changes to the document even after closing and reopening the document.

4. Working on a document where I needed to replace two pages. Would not let me delete the two pages. This was a document that I created with no restrictions in place.

HELP!