There is no reason to have pieces of different lengths unless you personally want that.... and if you change too quick that WILL tip people off.

Just style what you have different ways from time to time.... and when you get your real growing side and back hair cut it gives you the illusion of a haircut all over, trust me.

The comment about hair not growing doesn't raise a good point, it proves the person saying it doesn't have a clue what they're talking about.

No piece is undetectable to lots of touching, but you can absolutely make it so that no one can tell if you are wearing or not by sight alone.