freebsd stable - Apr 2016 - Curious about loader.conf variables that I had to edit out

Cross-posting two thee lists (here latter two, so more who
may know may read...)

These settings removed, from /boot/loader.conf, fixed a hosed current/custom
kernel bootup (v11 of April 2016) that was a showstopper here... so one of
those lines below may be an obvious problem someone knows about (either
the sysctl, or value assigned to it...) 

Otherwise, some/all may be fodder for one's own loader.conf if they are
viable;  each had a reason per a website or blog or wiki or list email
obviously, at one time.  (twelve years in compilation altogether so far...)

# out snd_pcm_load="YES"
# out snd_acm_load="YES"
# out kern.msgbufsize="130000"
# out kern.ipc.shmmni="1024"
# out kern.ipc.shmseg="1024"
# out hw.snd.maxautovchans="4"
# out hw.snd.targetirqrate="36"    
# out hint.pcm.0.buffersize="65536" 
# out hw.snd.verbose="3"
# out kern.ipc.semmns="240"
# out kern.ipc.semume="40"
# out kern.ipc.semmnu="120"
# out vfs.read_max="128"    
# out kern.randompid="1"
# out kern.ipc.shmmax="67108864" 
# out kern.ipc.shmall="32768"
# out vm.kmem_size="700M"    
# out vm.kmem_size_max="700M"  
# out vfs.zfs.arc_max="250M"
# out kern.sched.preempt_thresh="224"
# out vfs.usermount="1"   
# out kern.geom.part.check_integrity="0"  
# out vm.overcommit="1"
# out kern.maxfilesperproc="65536"
# out kern.ipc.somaxconn="1024"
# out kern.ipc.nmbclusters="81920"
# out kern.fallback_elf_brand="3"
# out vfs.write_behind="0"

Not urgent but may save some time and trouble if I am
careless upon uncommenting the line and it all goes
south... from a PBKAC or similar.