POP Mail help

Ok guys I need help with remote mail.

1) I would like to give my users the ability to have their mail while on the road (solution -offline folders - PST)
2) The ability to download their mail (POP mail. Can't use IMAP because they have desktop PCs in the office, so the mail needs to stay in the server)

Questions??

If I have Their POP mail delivered to their PST files would there be a problem if they try to sync in the office?

Would the emails already downloaded thru POP be duplicated since they are still in the server or would the sync function figure out it's the same message and not duplicate?

When a user sends an email on the road using POP mail and saves a copy in their sent folder would a copy transfer to the server when they sync their PST folders in the office?

I hope this makes sense.

Thanks,

Rick

P.S. I know VPN would be the best solution but management wants to hold off for a while.