Just to be perfectly clear (was this stickied? I can't seem to find it in a guide!)
- If I install a game on my own, that should be playable if there is no mandatory update/additional item that makes the game playable >5.05
- I can update with only legit updates
- I can only get those legit updates through one of the sites you listed.
I am guessing there's no way to take the thing PS4 online and try to patch it that way since 1) the console will try to update too and 2) updates will just push it to the latest version, which will require a new FW anyway?
1, you can install base games of version 1.00 which require 1.76 or lower FW and they work fine, no need to update games, no requirement.
2, is you have the disc or paid for psn title that still loads, you can update with legit updates. Otherwise fake signed games need fake signed updates.
3, As Sony doesn’t archive its older fw compatible patches: yeah you need to use a site that did.
4, no can’t update games without psn access, and they would generally require latest FW to install.