How long can you go? Depends on what you mean by "shooter". What's the current length, your draw length and approx. draw weight? How much will you need to shorten the bow? How 'stuck' are you on the current draw weight? What was the purpose of this bow -- big game hunting, small game hunting, formal target shooting, backyard roving?
If you shorten, you'll gain about 5# of draw weight for each inch you take off the ends. So to maintain the draw weight you'll have to re-tiller.
I personally like light draw short bows -- 52" for me is a long bow. My draw length is 27" -- I do not draw to the ear, but to the tip of my jaw. I'm not a hunter, I'm a backyard rover, and I'd rather shoot 100 arrows a day with a 30# bow than 10 arrows with a 70#er.