There will definitely be no problems if you will take creatine - it is one of the safest supplements out there, and the biggest problem you can expect with it is some water retention due to heavy overdosing, or due to not drinking enough water everyday.
Regarding the protein, it is by far not a necessity, and you should use it only as a supplement that will fill in the gaps in your diet. If your diet is fine, then there is no need for protein supplements. In the end of the day, if you will be taking protein just for the sake of taking it, without a real need for it, you will gain weight.