You CAN get rid of the noise of ejection, BUT in doing so, you change the ejector to an extractor only. You do it by backing off the ejector spring tension screw until it no longer clicks when you drop the block! If you want ejection, you get the click along with it. However, the ejector spring screw is adjustable to give whatever degree of ejection power you want, from none to putting the case into the next county!
As for accuracy, a two-piece Mannlicher stock is not as bad as a Mann. one-piece stock. On the No.1 RSI, the same forend treatment approach that is used on the other models works with the Mann. style as well. That is, an adjustable forend hanger tensioner block between the barrel and the tip of the forend hanger.
Yes, you will lose some velocity due to the shorter barrel, and muzzle blast will be greater. But the 7X57 is not as bad in these regards as the .270 or .30/'06, which are also make in the RSI. Some of these disadvantages can be made up by judicious handloading. But of course, if you INCREASE muzzle velocity to compensate for barrel length, you will also be increasing muzzle blast at the same time.