-the one that is dearest to me is the unbalance between the k98k and the russian counterpart the mosin nagant. Rifleman is my favourite class and thus I play mostly in that role, and I must say that it is damaged by an unfair balance between the two rifles: the k98 was a modern bolt action carabine for the time, it was light, accurate, fast, and short. Because of those reasons it should be more accurate than the mosin nagant (a late '800 long, heavy, old rifle), and it should also have much less sway. Moreover you should correct the fact that at close range the k98 shoots higher than were it actually aims.
Have you ever actually fired any real K98s and M91/30s? I have a few examples of each and can say that with regard to practical accuracy there is very little difference. I would agree that on average, a K98 may be expected to be
slightly more accurate than a 91/30, but the margin is slim. From a solid rest, either can be expected to group all of its shots into an area smaller than a human head at 100 meters, and most of the time at 200 meters.
The K98 does have a more modern and refined action. The bolt works more smoothly, and the rimless rounds are held onto the stripper clips by spring tension and slip into the magazine more smoothly than the Mosin's rimmed rounds, which are held into the clip by friction. The Mauser action can therefore probably be worked a little more quickly than the Mosin's, and reloading accomplished a little more quickly, but again it's a slight difference.
One area where the Mosin has an advantage, in my opinion, is the sights. In real life, they tend to be quicker to align and allow for more precise aiming than the Mauser's. The Mauser has a better trigger, however, usually with a lighter and almost always a crisper action than the long and spongy feeling Mosin trigger, so this gives an edge to the Mauser for precise shooting.
As for weight and balance, there is not a lot of difference. The Mosin is longer, but not so much that it feels particularly awkward. It's longer, but it also feels a little slimmer in the hands. The 91/30 is significantly shorter than the original M91 which was used in WWI. (The G98 used by the Germans in WWI was also quite a bit longer than the K98.) The weight of the K98 and the 91/30 has always felt about the same to me. Out of curiosity I looked it up on a couple of sources. Wikipedia lists the weight of the K98 at 3.7 to 4.1 kg, and the length at 1110mm, and the weight of the 91/30 at 4kg and the length at 1232mm. World.guns.ru puts the K98 at 3.92kg and 1101mm, and the 91/30 at 3.9kg and 1234mm.