Can I rename the "Pictures" folder without "Full Disk Access"? Our application needs write access to the user's Home directory, specifically to Pictures, Movies, Music, etc., so it can redirect them to our cloud support. But, on Mojave, renaming Pictures (to some back-up folder) fails with EPERM without the Full Disk Access right, which seems too much and too hard to acquire (cf "Unfortunately, Apple has intentionally designed the process of granting Full Disk Access to be difficult, so that users are discouraged from granting Full Disk Access unless absolutely necessary." seen here). Is there another way ?
If you want to do this as a regular user running in standard mode, then no - you have to ask the user to grant permission via Full Disk Access.

You can do it through other means by booting the Mac in Recovery mode for example, but I assume this is not something you want to do as part of a standard process. Granting the correct permissions is way easier.

Note that it is possible to grant the permission, make the change, and then remove the permissions again. This will help if you feel that it is too permissive to allow this software Full Disk Access forever.