If you used Insert | Picture | From File and didn't specifically choose to
link them, then they are embedded. If you pasted them in (from the Web,
say), then they are probably linked. If they're In Line With Text, you can
tell by pressing Alt+F7 to see whether the INCLUDEPICTURE field shows a file
path; if they're wrapped, you have to make them inline before you can see
this. But the likelihood is that they're embedded, so that's probably not an
issue.
The reason I asked about version is that if you had saved the document in
Word 2007 format, users of earlier versions wouldn't be able to open them
without having the Compatibility Pack installed (though the file shouldn't
crash Word, even so).
If the recipients have Word 2003, you could suggest that they try using the
Open and Repair option. Alternatively, if the files were emailed, they may
have been damaged in transit; zipping them before sending might add another
layer of protection against damage.
Also, the recipients shouldn't be trying to "open" the template you sent.
They should be saving it to their Templates folder and using it to base new
documents on.
I'm afraid I'm kind of out of ideas, but if you want to send the file to me,
I'll see whether it crashes my Word!