I bought a long stick once, just for fun. I'm 6'3" and the thing was almost as tall as I was.
Over the life of that stick (a couple months) I couldn't take a decent slapshot to save my life. Was just way too long of a stick to do that. If you like blasting shots from the point as a defenceman, forget it. I'm sure it could be done with lots of practice and/or changing my technique significantly, or maybe I just sucked.
I always made sure my spare stick was a regular-length one, just so on power plays and such I *could* take some good shots.
In my own zone I loved the thing. Poke checks, sweep checks, stick-down... that extra length was amazing. When opposing forwards were in close I wouldn't be able to touch the puck (like you said), but was still able to lift their sticks. Didn't take too long to get into that different frame of mind (attack the opponent's stick instead of the puck itself).
If its so long you can't play with it...cut it. IMO its rediculous you'd be out there with a stick that you cannot even shoot with.
It's not ridiculous. Some people can play with such long sticks. Whatever works best for you. True, it takes time to adapt, but a long stick has quite a few advantages. Slava Bykow, a world class russian player in the 80' and 90', played with sticks that ended above his head. He was amazing to watch.
I started playing a few years back using a stick that went up to my eyebrows. It allowed me a great poke check, but little else.
I started cutting them down to my nose, which improved stickhandling and shooting without impacting my defense. And then I cut down again to my mouth, and now I'm down to my chin.
Occasionally I have difficulty with catching passes or pulling moves while stickhandling with the shorter stick, but my shot is much better. I put a 1" plug in for the last couple weeks, but my shot suffered so much that I'm taking it back out.
I will say that my lower lie stick plays like a longer stick because it is closer to being an extension of the shaft, so I can keep the shorter length with fewer problems.
But it's all about your preferences, if you can stickhandle, shoot, and all that with a long stick versus short, go for it.
I would personally use a short stick. Besides reach, there isnt that much more of a difference than using a short stick. I started playing with a long stick for 2 years. then cut it down. Now I have better puck control and quicker release and passing. Its like night and day.
Stick length isn't pegged directly with going up to your groin, shoulders, chin or anything.
But one reliable guide is to take a look at the tape on the bottom of your blade. It should be wearing out from the middle or fairly evenly.
If it's wearing out mostly at the heel, you'll want a shorter stick or a lower blade lie. (e.g. go from a 6 to a 5.5)
If the tape is wearing more at the toe, you want a longer stick or a higher blade lie.