Hi, i intend to do a full mirror feature facing the dining area but this means part of my mirror will be facing my main door. Will this be ok?

Hi Jac, you can have your mirrors anywhere you want and it will be fine. Mirrors will not affect Feng Shui (they reflect light, not Qi; Qi is not light). On a psychological note though, some people have been known to scare themselves in the night when they see their own reflections! Other than that, have fun with your decor. Cheers!