Layers in long hair?

Hi everyone. Id like to get all the facts and opinions possible before I go ahead wth this.

I have dark straight long thick hair. The lentgh is to my waist. I am thinking of having it cut 3inchs and then layered.

Im thinking of telling the hairdresser that Id like the layers to begin just below my chin and getting longer in steps.

What do you all think??? Also, should I get it thinnned out?

And Is there such thing as too many layers???

Thanks in advance, harv