I have shot the 9.5 Mannlicher which is pretty much the same thing and same sort of weight. Yes it kicked, but no more than say a 12 bore side by side with an 1 1/8 or 1 1/4 oz load when you take a carefully aimed stationary shot. I doubt you will notice in on a boar.

Mannlichers were generally fitted with either a swing mount or a claw mounts, with the front base affixed to the barrel in front of the action. These are not going to be cheap.

But for a 9.3 its meant to be used on big game at shorter distances so buy it and use the open sights.

Re fixing - there is somebody in Austria remaking these rifles I believe. There will be spare parts about if needed. As for the stock - if it was going to break / crack it would have done so by now. If it does crack, well it can always be glued and pinned so that it will be stronger. Most cracking is caused by a loose action, possibly due to wood drying out too much.