I feel that it's a must to kneel to my parents and FPILs during tea ceremony because it's them who raise my FH and I up. But by kneeling down to the other elders during tea ceremony, it doesn't signify any special meaning. If I need to kneel to the elders, I will definitely faint because I have so many elders to kneel (at least 25 times up and down). Yes, I respect them so I offer them tea during the tea ceremony. If they force me, then it's them who "mei jia jiao".