You can email [email protected] if you wish to try. Yes, it no longer works for Kodi 17, but ok for Kodi 16. Try using the Xtream-codes add-on instead.
Probably not. The script doesn't allow for the redirects at the server. I hate to say it, but IPTV Stalker is now dead. (Probably fixable, but there is no reason to do so, except maybe to filter VoD.)
Using portal1 or portal 2 will currently bomb, other portals will work, but that will stop, according to the announcement.
If you want to use a video add-on, you can use any add-on that uses m3u lists (or a link that will generate the list), or xtream-codes IPTV. There are posted tutorials for that on the site.
PVR Stalker has been reported to work by other members, but I don't know for sure on NFPS, yet.