Your usages are not limited; except you cannot use the application on more than 5 devices, unless the license clearly says you can use it on more devices. [...]
Therefore, I think it is quite safe, now, to publish a FOSS application on the Windows Store.
This surprises me a bit - doesn't the GNU GPL explicitly state that you cannot impose any further usage restrictions other than the ones states in the GPL?
This surprises me a bit - doesn't the GNU GPL explicitly state that you cannot impose any further usage restrictions other than the ones states in the GPL?
(That is the reason the GNU GPL is not compatible with the original BSD license: http://www.gnu.org/licenses/gpl-faq.html#OrigBSD)
Not being able to run the app on more than 5 devices is certainly a restriction.