I bought a 1960s Yamaha U1 about a year ago, and really like it. However, it's slightly too loud for the room it's in. I noticed it has a wing nut on the soft pedal that can be loosened, and this reduces the volume by moving the hammers closer to the strings (essentially like having the soft pedal slightly depressed all the time). This means that the mechanism is no longer resting on the felt, and is instead being held up by the pedal and the stainless steel bars in the picture below. Is this likely to cause any problem or damage something?
On a related subject, I had noticed the keys quite heavy on the U1, heavier than my previous piano (a smaller, much newer Yamaha). This left it quite difficult to control how soft a note sounds, either it was quite hard or very soft, sometimes missing. Is this just a question of practice or should I get it regulated in some way? Pre-tensioning the soft pedal also improves this.