I have been looking at this post with some interest and there has been some interesting things said for and against it.
I think that it would be great to see what a single piece of Hickory could withstand in a bow and good luck with making it, I look forward to seeing it.
With regards shooting it...well I doubt there is anyone who could draw it to the full 32", The compressive forces on the body would be immense and could be harmfull if the person had not trained specifically for it.
With regards getting the draw length up to 32", well that on its own would be good to see, I am very good friends with Mark Stretton and drawing thatr 200# bow nearly killed him and very nearly stopped him shooting full stop.
Ryoon...To you I would say take it slowly, you may have the muscle strength to move a 120 bow to your chin with just the strength in your arms, but that is where things get difficult as unless you are 4' wide at the shoulders you will need to rotate your shoulder to gain the 32" draw length, this puts massive stress on the shoulder joint, Also the bow arm, You suggested that you need to straighten your arm to get the draw length...well I'm afraid that is the worst thing you can do as you are then in a situation where you are placing all of the load on the elbow joint on your bow arm and you will destroy your elbow joint very quickly...result never shoot again.
The other thing you need to take into consideration is your wrist tendon strength, you may have strong arm muscles but the tendons in your wrist on the drawing hand will need many years of repeated practice to strengthen to the point you dont snap them.
I'm not trying to be too negative here but just wanted to point out that these heavy bows can do a lot of damage to your body if you dont take it slow.
Here is a picture of me shooting a 120# bow, you will see the bow arm is not straight and I am drawing to 32", as I am not wide across the shoulders I have to rotate my shoulder blade to the extreme. Anyway I wish you luck with your attempts and be careful.