We never need to touch the arch. model itself, so it seems like it would make sense to have a choice somewhere that would make it unselectable.
1. You can log in as a "User X" create a workset Links and put the linked files on it. Save to Central without Relinquishing. Go back and log in with your normal login. You will still be able to select the links but not modify them.
2. Create Design Option and put the link in it. You will not be able to even select the file.
LKJones you missed the solution further up the list of replies. PHristov second option works perfectly and will solve your problem revitman. Create a design option and add any links you don't want to be able to select to the option. Switch back to the main model design option and the links will now be totally unselectable. Thanks very much PHristov, that solves a problem I have been struggling with for a while now.