Where can I check whether the WSFC configuration is configured such that it performs dynamic quorum and dynamic witness?
If you are using Windows Server 2012 R2 both are enabled by default. You would have to actually setup a WSFC to actually see how it works. Below links can help you in your testing
Till windows server 2016 you have option on cluster configuration page to
Allow cluster to dynamically manage the assignment of node votes option you can enable or disable it. But i would never disable it. Dynamic witness is boon as it does the manual task of toggling the votes in case of node failure to automatic.
and there is no choice to disable it
There is, but actually it is not a choice in form of toggle button. When configuring cluster and configuring witness you see below option
do not configure a quorum witness and this feature will not work but remember you are not configuring witness here. I again suggest you to read WSFC’s Dynamic Witness in Windows Server 2012 R2