CJ2311

I think screenshots would be more useful in this case, so here you go:
 
1. This is what I get after right clcking on check for errors with a (semi)empty amidianborn_skyforge_weapons.esp (so that's basically what I have at step 5.
https://i.imgur.com/mxQ3QqC.png
 
As you can see, there are 2 errors, one with 11002DC5 (skyforge steel shield), and one with 110022F6 (Wolf shield) in STEP Extended Patch (since those 2 records were in amidianborn_skyforge_weapons.esp and now TES5Edit can't find them since they've been deleted)
 
You can also see that I highlighted a line that mentioned quests, that's what I was referring to when I said to ignore quests, so we'll not be deleting the 00023B6C and 0004D8D6 records. (since they're both quests)
 
2. Here you can see the two corresponding records (11002DC5 and 110022F6) on the left pane.
https://i.imgur.com/nobLyIl.png
 
Simply right click on these two and select remove, then save the file, and you should be fine.
 
Note that this method doesn't always work though

Both are possible.
If you want to do it via a patch, simply select the lamp record in T5E, copy it as an override in a new file, and then put the disable flag + Z coordinate = -30k in the new file.

No no, you only need to set up shortcuts in MO to use programs through it.
 
Here's the official guide for that: https://wiki.step-project.com/Guide:Mod_Organizer#tab=Third_Party_Programs

Use the fomod installer by Tannin, not the Nexus Mod Manager one.
 
How-to:
Click the Settings button in MO (The icon with a wrench and a screwdriver).
Click the Plugins tab.
Select "Fomod Installer" in the list.
Double click on "enabled" and set it to "true".
Double click on "prefer" and set it to "true".
Hit OK, and install the REGS patch.
 
 
Don't know why it's not working with the NMM installer to be honest, especially considering the actual NMM handles the "typeDescriptor" just well :|

Creation Kit is needed for almost everything. So is TES5Edit.
NifTools used alone is useful for changing an existing model's texture.
Blender (or GMax, which I don't recommend btw) + NifTools + Photoshop (or The Gimp) are used to create new models and textures.
Some tutorials can be found on the creation kit site, Bethesda's YT channel, or BestinSlot's YT channel.
You can find more tutorials by using google.