Starting with your Finder issue, open Finder and go in Finder/Preferences/Side Bar, here you can customize the settings and add/remove what you want to see.
Now proceed step by step:
Download the attached files in a folder on the Desktop
Go in L/E, made a backup copy on of:
"AHCI_3rdParty_eSATA.kext" "AHCI_3rdParty_SATA.kext" "FakeSMC.kext"
in the same folder You have downloaded the files and delete it from L/E
Copy FakeSMC.kext and AppleRTL8169Ethernet.kext in EFI/CLOVER/kexts/10.11.
Open "Terminal" and to rebuild cache copy/paste this command:
sudo touch /System/Library/Extensions
Hit "Enter", close the app and reboot.
Control if your second Ethernet appeared.
Now with your preferred method "install" aDummyHDA.kext in S/L/E (from what I've seen it is working only from here), copy DSDT.aml in EFI/CLOVER/ACPI/patched (attention, NOT in origin), replace the config in EFI/CLOVER with mine, and repeat with "Terminal" :
sudo touch /System/Library/Extensions
Reboot, go in "System Preferences/Sound" and in Output chose the one you have connect your speaker.
It should be all working fine, take a closer look of your system and let me know.
(I recommend to carefully follow every step)