Does hosting guests at home with meat and alcohol (because they are fond of it) amount to aiding the guests break their Sila?
"So, when I host a party at my place, it becomes obligatory of me to host them with alcohol and non-vegetarian food (bought from a restaurant). "

I don't see how it is obligatory. You could serve delicious vegetarian food and non-alcoholic drinks. If you take your Buddhist precepts you are not supposed break them yourself or encourage others to break them. I think your instincts on this are correct. 

Would it be so boring? Have you spoken to your friends about this? Why not raise the subject and see what they say?