Q: User set as local home directory symlinking back to network

Apologies.. this is a bit of a long one.

Short version.. how do i get a user who has their home directory set as local inside WGM to have all their home directory folders (maybe except a few) symlinked back to a directory on a network share?

Long version....

For years now we have been running network homes with no major problems. However we are now migrating our email from the mail system on our servers over to an office 365 service supplied by our main corporate IT department. Along with this we get access to the latest Office suite. These apps authenticate to the corporate servers when you launch them and use the user's credentials to check for licenses and authorise the computer appropriately. However, for some reason that no-one appears to be able to answer, this will not work when using a network home. The keychain appears to be sandboxed and won't allow the app to write to the keychain it needs to, and so fails with a 'no credentials available' error. All works perfectly well on a network user with their home directory set as local. Also adding the mail account to Mail via and exchange account also fails to authenticate.

So effectively i'm trying to think of a way that i can continue to have the advantages of network homes (hot desking being the major one along with quick solution if a user's machine goes down) but with everything thinking that it's running on a local account.

I've tried using login hooks but it appears that it's not possible to overwrite the home folders once you've logged in as the OS is using them.

I can't seem to find the right paths to put into MCX folder redirections to get it to work. My thought was to use /network/servers/example.com/volumes/users/%@/ etc as a symlink target but if you navigate through that folder list you find that the home directory has an unknown user and group (which appears to be wheel:root if you look in terminal) and so obviously the user cannot access it.

I haven't really looked much into launchd as i'm assuming i'll run across the same issues as login hooks.

Server is running 10.7.5 (hardware limited), client machines are all 10.10 and above (was decided by Konica Minolta not making printer drivers that worked for anything less that 10.10 )

In the long run i'm trying to move away from the xserves (the mail migration was step one of this) and was hoping to just have a pair of mac minis solely just doing user authentication and then just pointing the clients to a network share on whatever to access their home directories. Appears that apple has decided that network homes are no longer something they're supporting.