Respecting one's guests

Q: How should one treat ones guest? Does the guest have any rights? Does the Ahadiths mention any thing regarding ones guest also if one shows disrespect to his / hers guest is it a sin? Is it correct to ask if you'll will have anything? If mufti saheb could narrate any incedient in the live of nabi [Sallallahu Alayhi Wasallam], the sahabaa [Radiyallahu Anhum] and in the lives of great uleama of deoband on how they took care of their respected guess?

Gheebat

Q: I have a question that I have a distant uncle who is sick and old and that when I  inquired about his health from my brother over the phone he said that he's not well and doesn't recognise people, today when I met with another relative he was asking me about this uncle and I said that he's not well and that he doesn't recognise people. My question is that is it a gheebat (backbite)?  Please advice me.