Comment 5 for bug 492815

Just putting an idea here:

What about adding a "lock" option? Basically all operations would be permitted (add, modify, move, rename) except delete.
In U1 application this would be shown as a second tick-box in the folder view, in a column named "allow deletion".
The default behaviour (box ticked or unticked) would be configured during U1 initial setup. This would be useful for all user, especially when dealing with "ultra-critical folders" that you would hate to see disappear by user mistake.

For the OP: you might want to look at u1ftp while people are working on your bug. Because it's ftp there is no synchronisation nor instant opening/modification but it would help on your usage. It's not as easy to use as U1 but it's a start I guess.