1) It is fun and feels nice / is appreciated to make food for friends and family.
2) I ballpark what I might want when grocery shopping but generally make serious plans for a meal for several people.
3) Sous vide chicken is currently popular. Grilling and smoking meats is the second most popular food prep I do, with baking or pan-frying fish a third.
4) No but I stay away from red meats, pork, and carbs because I feel better not eating them (so chicken fish and vegetables are most of the menu with some grains).
5) I'll agree with others - cooking is a fun event for friends to participate in.