be careful when ordering DW1510 from china i just received 2 in this week and they had a VOID sticker over it which i found suspicious. when i peeled it back it was an unsupported wifi card DW1397 instead. not worth my time to ship back.
i wonder if this still has any merit with the new os's http://www.insanelymac.com/forum/topic/237068-usb-card-reader-apple-optimized-legacy-driver-1065106610671068/page-1
the volume and brightness keys keys are probably remapped to other Function keys try different combinations using the FN key plus all the F keys and other keys you dont normally use like insert, pgdn, ect..
run this command first to make sure you do not have a core storage disk
diskutil cs list
if it finds a core storage volume and you only have 1 disk and osx is on disk0s1 then
diskutil corestorage revert /dev/disk1
you can also check to see if . the volume is blessed
bless --info /Volumes/volume name/
if it returns with all zeros 0 => then it might need to be blessed wich is apple form of allowing a volume to be bootable
sudo bless --bless /Volumes/Volume name/
for windows here are a few sugestions
http://serverfault.com/questions/276076/how-can-i-un-mark-a-partition-as-active
you can probably do it from a windows installer command prompt
unsetting an active partition in osx there is no straight forward way to do it without installing windows or linux binarys made to work on osx like fdisk or gparted or gpt-sync as OSX does not use an MBR partition
i believe audio device 0x80860c0c is an unsupported HDMI option in OS X. even though you see voodoo hda attaches to it. it will not work. you can modify voodoo hda plist to only attach to 80868C20 by changing "IOPCIClassMatch" to "IOPCIPrimaryMatch" and put the PCI ID of your audio card in string which is 0x80868C20.
i guess the simplest way check is with a linux distro with gparted or disk utility. anything else in osx will probably entail terminal commands and maybe gpt fdisc. or just reinstalling the whole os after a disc wipe/ repartitioning.
have you tried using an elevated command prompt in windows and running the bios exe with the forceit command.
first cd into the bios directory then use the name of the exe with /forceit
biosflashname.exe /forceit
you can try some of these switches to see if they work
http://mickitblog.blogspot.com/2011/09/dell-bios-switches.html
i know there used to be a way to force flash the "D" series using the "HDR" file on a usb, removing the battery and holding some keys while powering up but i have forgotten how to do it.
it was similar to the 6th post here https://www.bios-mods.com/forum/archive/index.php?thread-16768.html
you can try this to reset the bios http://www.dell.com/support/article/us/en/4/SLN245206/ru
this is for certain models.
http://www.dell.com/support/article/us/en/4/SLN300716/en
if using clover check your kexts to patch patches to see if they have match os set as it might be patching for wrong os. not all patches transfer from os to os. some of the patches for wifi are for sierra only and at that certain versions like 10.12.1 or 2
what boot loader are you using? if using clover check your congif.plist and nvram for backlight level and remove it. if using chameleon you might have to repatch your framebuffers
terminal command
networksetup -setairportpower airport on
you can also try replacing "airport" for "en0" or "en1" (with out "quotes") depending on what your airport is stated as. changing on for off will disable wifi.
did you install the kexts to Library/Extensions from the efi/clover/kexts/other/LE folder ?
also make sure that you do not have the hardware disabled in bios or the switch off