As a starter answer.. I would suggest the following.
1) sshfs doesn't require access to the /etc/fstab, so if you can map your webdav users onto linux users with similar file structure, then that is a simple alternative.
Then you can use non-root syntax like this to mount within your local home directory;
sshfs -o ControlPath=none -o workaround=rename -o idmap=user \
-o nonempty -o reconnect -o transform_symlinks -o follow_symlinks" \
2) gvfs/gio - Depending on your distro,
/usr/libexec/gvfsd-dav might be an option, which should allow an alternative control syntax to mount the webdav filesystem under
However the documentation is pretty rubbish, and I've only made a limited test of its functionality like so;
sudo yum install gvfs-fuse.x86_64
then as a user;
$ gvfs-mount dav://my.dav.server.hostname.com/projects/
Enter password for Authorization Realm
$ cd ~/.gvfs/WebDAV\ on\ my.dav.server.hostname.com/