Run id to double check the user and group IDs of your accounts on both your local and remote systems. I'm guessing they're different, even if the names are the same. In that case FUSE is trying to modify the local mount point as an other user, as far as chmod and permissions are concerned. Therefore, you need to chmod o+rx ~/fusessh. The mode (permissions) of this mount point will be modified by the mode of the root of the filesystem that you mount, otherwise the directory should be empty if nothing is mounted, so giving other read and execute permissions shouldn't be much of a security risk.

In order to unmount, every directory in the mount path needs to have execute permissions. Run realpath ~/fusessh, then make sure that each directory in that path has the execute bit set for other (still assuming that UID/GID are different on each system).

Note: I post this now because I encountered these exact same issues today. To be honest, I don't know exactly how FUSE works under the hood. In my case the UID was the same on both systems, but the GID differed. Still, nothing worked until I gave permissions to other. I experimented with the uid, gid, and default_permissions mount options, but none of those fixed the issues. It seems to me that those mount options only changed their respective attributes after the filesystem was mounted, but that FUSE was operating under the UID/GID of the remote system before the mount finalized. Again, this is only speculation, but it fits the behavior.