Oddly enough, archery done correctly doesn't use the shoulders so much as the back muscles - I was trained to squeeze my shoulder blades together at full draw rather than use my arms and shoulders. Now, that was years ago and nowadays with modern compound bows allowing about a 70% let off at full draw, things have got a little easier on the body!
If you want to have a go at bending a bow, I would suggest you rock up to a proper archery club - bow hunters or target - on a come and try day and have a crack under proper supervision.... the coaches are generally pretty good!