Hey there,
I don't know if this has been reported yet or is being worked on so I'll just assume that "no" is the answer to both and post this suggestion here:

WCF 2.1.14
WBB 4.1.13
FCMS 2.1.0

Using the latest version available here the Fireball CMS pages return an "invalid url" (cms/page/<page>) error when "Link compatibility is turned off in the acp" (which it is by default).

Activating this "mode" enforces the WCF 2.0 url style index.php/Thread/123-Title/ and disables the 2.1+ variant (index.php?thread/123-title/)

On a first look this doesn't break anything but I bet there's a reason why the WCF devs changed the syntax.

Using the rewrite mode one can turn the CMS URLs back to cms/index.php/<page>/ which does work out but doesn't seem to be very user-friendly.
This also disables the ability to rename controllers resulting in our German board using English URLs which also isn't desirable on the long term for us.

Maybe you can take a look into that when time's there.

Greetings from Germany