Is that the amazon fire box you mean mate ??Install this for the TV guide: https://seo-michael.co.uk/tutorial-how-to-install-setup-ftv-guide-kodi-xbmc/
On the buffering side of things; it's likely just the streams you are using; perhaps an upgrade to the new 4k fire TV might improve the situation but I honestly doubt it; unless anyone else can say otherwise from experience :)