Printing using Netgear ReadySHARE Print function is not working.

> [...] "Instalation incomplete. Please install again." [...]

   Not "Installation is incomplete! Please reinstall again."?

   This has been reported here before, without obvious effect.

> I thought that maybe this is a firmware issue [...]

   Inability to install (defective) software on your Mac has nothing to
do with your router.

> I'm using a Nighthawk C7000-100NAS Modem/Wireless Router [...]

   A cable-TV ISP has complete control over the firmware of any
modem(+router) on its network.  There is nothing you can (or need to) do
about it.  If you have any doubts, then contact your ISP.

> [...] Any tips, tricks, workarounds, or other suggestions?

   Complain to Netgear about the Mac software installation problem?