How to handle two different cultures

Can you pick one or two traditions from each culture and incorporate those into your wedding? That way it will reflect the two of you as well. And in terms of the food, why not have food from one culture at your rehearsal dinner, and the other at your reception? Or have Vietnamese style food during cocktail hour and Italian style food for the dinner proper?

I dont really think you should focus on making others happy. Its your wedding and the most important thing is that the both of you get what you want out of your day. My FH and I are also from different cultures, I am Russian and he is Italian. We are having our wedding at a hall which also caters the food, the food is mostly Italian and there are 11 dinner options so Im sure people will find what they like. For the reception however we are hiring an additional mc who speaks Russian to speak during some parts of the wedding or rather translate for those who will not understand such as my grandparents. Maybe you can do something similar such as incorporating music from both of your cultures.