shney lechem etc on shabbat etc

Question

Hello, In this very liberal orthdox shul, after davening, the rabbi onthe bimah makes kiddush and washes andmakes motzi, standing, on to hallot, and then we go into the social hall for what is usually a very full kiddush-lunch. 1. Can i eat at this reception, even if I dont drink any wine, or eat any challah? and when i go home, and am full, should I later, say motzi over shney lechem(=for me, two matzot) later in the afternoon? I am single, and it is a real break not to bother to cook for myself. 2. if they do have pita-tuna sandwiches, i do wash go off in a cornter to sit down and make a motzi, stand wander around and talk, and go back to where i was sitting and bentch. I dont wait around for the rabbi and his group to bentch, they can stay there forever, and it is a long walk is this correct. 3. must i have bread at shalosh seudot ifi had bread earlier? thank you..... again i complliment you for pskening to the point, and for being open to all questions, unlike Yeshiva i went to...they seemed to pasken according to what they wanted the halachah to be