I have developed extensive Excel 2003 VBA addins. I'm planning my Excel
2003 - 2007 upgrade and have a couple general questions to start with:

1. Will Excel 2003 addins work in Excel 2007?

I hope I can load my 2003 addins in Excel 2007, save them and
reuse the saved version.
If things have changed, is there a list of items which have changed?

I use the addins to create reports. For example, I create a
customized excel menu from a table to access my specialized functions,
insert
excel worksheets and update the excel names when the worksheet is inserted
to use the parent workbook's names, have implented a 2d sketch package on
top of the excel drawing functions, etc. In general, my addins would be
considered advanced VBA usage.

2. Is there a method in Excel 2007 to prevent users from accessing the addin
contents?

I want to distribute my addin's, but I want to keep the addin contents
private.
In Excel 2003, you could add a password but there are numerous tools which
will crack your password. There was no way to keep the addin contents
private.
I was hoping for a compile/binary option in Excel 2007 to keep the addin
contents private.

thanks.