You shouldn't expect to find any incompatibilities with Debian 8. This is purely from a kernel and Java perspective. I believe version 8 uses systemd to manage startup, though I'm not sure if the old systemV (/etc/init.d) remains for backwards compatibility. Regardless, Wowza should create the startup scripts for you upon installation. Regarding license checks, the simple option is to not run Wowza on both servers simultaneously. You could always request a trial version and install that on the new server just to iron out any kinks then migrate your Wowza instance over once you're happy everything is functioning correctly.