First - and most important to the Chinese - the swastika is the mark of HANYANG (the usual transcription), the city where these rifles were built, not Hunyaug. Maybe it seems a bit picky, but Han is the mythical ancestor of the Chinese, so this is a pretty basic element. Or what would you think of a Chinese who wrote that the Statue of Liberty was in Naff Yolk Hardboard? Stick to the standard transcription - it makes it easier to find information.
Second - I once had to scrap a Chinese Mauser, for the same reason that is apparent in your example - the wood was appalling. Obviously not properly matured, and a poor cut, developing shakes from the shrinkage and a twisted grain - as you can see at the back end of the butt. This looks horrible, but is essentially cosmetic.
But the crack that would soon become dramaric if you were so adventurous as to fire it, is the one that starts behind the tang.
I do not think so. This is the classic Mauser split (not only in Mausers, of course) caused by recoil that is not being adequately taken up by the recoil bolt behind the front trigger guard screw. Wood shrinkage means that the tang, which should have a visible clearance in the recess in the stock, is tight against the stock and acts like a blunt wedge when the improperly located system is rammed back by recoil.
Over-enthusiastic restorers please note: this effect is the reason why you should NOT use force to try to remove the recoil bolt. All you will do in most cases is loosen its fit by the twisting action of unscrewing, which - if it is to be a shooter - may lead one day to such a crack. If it is stuck, let it be and clean around it.
But that is academic in this case. I would not even attempt to fire it. Based on the example I had in my hands and the photos of this example, it is strictly wallhanger material.