Q 2: What is the ruling on slaughtering a sacrifice for a guest since Allah (Exalted be He) says,
...and that on which Allâh's Name has not been mentioned while slaughtering, (that which has been slaughtered as a sacrifice for others than Allâh
Slaughtering a sacrifice for a guest is lawful as long as Allah's Name is mentioned on slaughtering it. The idea that it is offered to others besides Allah is totally wrong, as the slaughterer does not intend to slaughter it to get nearer to the guest, but he slaughters it (Part No. 1; Page No. 64) and Allah's Name is mentioned while slaughtering just to offer it as food to the guest. It is like the animal you slaughter to feed your family.