KF Multiple Issues KF Mac

hi, okay so like the title says im finding multiple issues.



im running a macbook pro 15 inch mid 2012, yosemite 10.10

2.3 GHz Intel Core i7, 4 GB 1600 MHz DDR3, Intel HD Graphics 4000 1024 MB/NVIDIA GeForce GT 650M



issues include:



-randomly crashing to the desktop



-bugged sound files (mixed up as in one sound file replacing another)



-stuttering lag. screen freezes then unfreezes for a split second every 2 - 3 seconds. sometimes more often (every 1 - 2 seconds) but never longer than a second or so



-cannot find my Steam or Killing Floor files on my laptop. ive looked in the usual places (users library application support etc) and have even done a search for the KillingFloor.ini file in finder & terminal, but it cannot locate any of my local files



-cannot change the brightness contrast or gamma in-game. moving the sliders does nothing.





any advice or help is appreciated!



thanks