The first thing you need to do is to fix the errors in your code. Even as stand-along macros, your ReplaceParagraphMarks and RemoveHeaders macros won't run. Both are missing:
If you then look at your ReplaceParagraphMarks, RemoveHeaders and RemoveBorders macros, you'll see that all have this much in common:
If you wanted to combine those three macros, all you need is the above code, plus whatever's between the With ... End With parts from each of those three macro (and, of course, a sub to contain all the code). That said, there are some other issues you need to address with the ReplaceParagraphMarks and RemoveHeaders macros, too. For example:
Selection.Rows.HeadingFormat = wdToggle
would only work on a Selection (i.e. something that is selected), but your code isn't selecting anything (and doesn't need to). Furthermore, it would actually add a header row if a selected row wasn't already one... Being inside a loop only means it'll keep toggling the same selection's header property on/off. Similarly, your Find/Replace code operates completely independently of any tables that it might be in - it works on the entire document. All that happens is that the loop keeps running the same document-wide process.

Finally, if you want to keep the macros separate, you could change lines like:
Application.Run MacroName:="ReplaceBullets"
to just:
ReplaceBullets
or, to make it more apparent another sub is being called:
Call ReplaceBullets

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]