hi,
i persoanlly think that "thank you" speech should be personalised. its really ok to have broken EHglish or Chinese so long as, the names are correct and why they deserve appreciations.
for example, you may like to thank brothers and sisters for lending them their listening for you to voice out your marriage blues.
XXX for helping with video montage etc.
if you have stage fright, you may pass your script to the emcee.
but, beofore you do a toast, personally take the mic and say :"thank you everyone" in both english and chinese will be sincere enough better than just standing on the stage and do nothing.