ANSWER:

You must not listen to your parents in this regard whatsoever!
If you pretend these things then you will end up with a woman who is like that and a non practicing Muslim and you would regret it for the rest of your marriage. 

My parents are looking for a suitable spouse for me; And in the process, they’re asking me to shorten my beard and to grow it back after marriage. They want me to appear as if I’m a moderate Muslim (i.e. watch movies and partake in free mixing) so that my would-be spouse likes me. But I hate to do this as it’s sinful. Please advise how I can convince them.