My bad indeed. Its "General" tab Well, if you dont want Memu to hog all your cores and leave some processing power to the system and other apps (Memu doesnt actually freeze your whole system even if you give it all cores. But its only me, i cant say for other people). Same with memory. You can just go to task manager and check how much memory your system and other apps use and allocate a percentage of free amount of memory (for example, 75% of unused memory amount). Or you could just set as much memory as Memu allows you. 1971 is a rather low amount in my experience, but if your game is stable and you can play normally, i guess you achieved your goal and should proceed to the event.
My sound is slower and sometimes produces static (rather often). I dont know why it happens (it also happened on other emulators when i was doing testing) and dont particularly care either. So as long as you can play at your normal pace and game\emulator doesnt freeze or crash on you often, i suggest you just ignore sound issues.