there is no impact on the car by removing the engine cover, you can buy replacement covers to fit with after market intakes like this to cover up the engine, not the sexiest but you can attach the silver tfsi from the original engine cover to make it look better.
the noise will increase by fitting most cold air intake some like it some don't, performance wise they will give you some gains but not massive.
not sure what mods you have, but I would put intake quite low down the list of priority after remap, exhaust, suspension
as there seem to be plenty of 300+hp cars without cold air intakes running very well.