Hi Karl,
I continued to mess with it and I was able to successfully get it to "A4" sizing with the crop tool via the two steps but I am still concerned about losing margin data. I am needing to convert 1000s of pages which is why I am trying to avoid losing my precious bookmarks haha Best thing I have been able to do is go back to my vendors and have them completely redo the data packages in A4 and re-bookmark them. I was thinking this was going to be quite convenient with Adobe but I thought in error. 
You can actually combine the two steps in an Action, and then run this Action on one or more files with just a couple of mouse clicks. If you want to upgrade to Acrobat DC Pro, that would give you access to the preflight fix. You can download and test a 30 day evaluation copy of Acrobat DC. Just make sure that you don't install it on a computer that already has Acrobat on, or be prepared to install that again from scratch.