I gather that there will be some differences in different localities but it would be useful to allow for R1 cast/crew lists to be able to be mirrored to other regions if required. Especially now with episode dividers, you are going to have to have people in each region entering the same information for the same titles.
By allowing mirroring of cast/crew any update to these fields will be ported over saving a lot of time and meaning that the information is much more likely to be correct.

Would this even be possible?

would still need to be verified, but slightly easier than doing a cut and paste

The trouble with copy and paste is that how do you know when a profile has been updated to go back and update?
At the moment I'm thinking of TV shows and the new episode dividers. I have TV shows from R1, R2 and R4. Having to check all releases to see if any of these have been updated can take a while.

Rather than trying to do it behind the scenes, maybe there could be an option to manually link a profiles cast & crew list to another profile so that when checking for updates it would check your local one and those you have selected to link to. That way instead of Invelos having to do it, you would select which profiles you wished to link to each other.

That's why in what I suggested, it would be you that would choose which profiles to link. For example my R2 Buffy season 1 I would select it to also check the R1 season 1 set for updates to cast & crew.