For autocorrects you can do this. Requires VBA. This version only substitutes plain text, not rich text. AFAIK it works on Win Word 2010 (and probably 2007/2013) and Mac Word 2011.
(Autocorrects basically only allow "rules" where one specific word is replaced by another text - as far as I know there are no facilities to check grammatical stuff such as plural versions of words, or to do any sort of wildcarding)
Create a Word document containing one table with two columns. Save your document.
Put "From" in the top cell of the first column.
Put "To" in the top cell of the second column.
Let's suppose you have 100 rules.
For each rule, you need one row in the table. Put the text you want to detect in the first cell of the row and the text you want to replace it by in the second cell of the row.
An autocorrect in this table will replace any existing autocorrect with the same "from", so be careful what you put in this table.
When you're done, save your work.
Then you need to insert the following VBA and run it. For some rather out-of-date assistance on that, see this link
Sub importautocorrects()
Dim objACE As Word.AutoCorrectEntry
Dim objDocument As Word.Document
Dim r As Word.Range
Dim objTable As Word.Table
Dim i As Integer
Set objDocument = ActiveDocument
Set objTable = objDocument.Tables(1)
For i = 2 To objTable.Rows.Count
With objTable.Rows(i)
Word.AutoCorrect.Entries.Add _
Left(.Cells(1).Range.Text, _
Len(.Cells(1).Range.Text) - 2), _
Left(.Cells(2).Range.Text, _
Len(.Cells(2).Range.Text) - 2)
End With
Next
Set objTable = Nothing
Set objDocument = Nothing
End Sub