How did you confirm this? Those methods should all work save for the EntityPlayer#playSound which doesnt work on the logical server you need to use another method. See here for more info.
I believe this has been a problem for a long time. It happens whenever the ItemStack changes. I'm thinking you might be able to use Item#shouldCauseRequipAnimation?
Why not use the ServerStartingEvent or ServerStartedEvent. They aren't part of the MOD event bus, but instead the FORGE event bus. They give you access to the MinecraftServer instance which both have a resource manager instance.
Until Mojang or another person/group come out with a Modding API for it yes. Except there are addons for it but it doesn't add new content it just allows for it to be modified.
A command line argument is something you but in the .bat file or .sh file when you start the server. Or for the launcher you edit the profile and you will see JVM ARGUMENTS. Put it there.
That's bedrock edition. I'm sorry forge is for Java edition. I don't believe there is a modding system out for bedrock(PC). But I could stand to be corrected.
This is the launcher in question have you run the version of Minecraft you are trying to install forge for. If not you need to. Its a simple verification that you own the game, and it also allows forge to legally apply it's changes to the game.
Have you tried using shaders? It sounds like they do what you want with some beautification as well. Maybe you'll have to write your own shader? Simply changing the range the torch lights up isn't a simple task. It already has the max range it can have. The only option you have would be to put "air" blocks that have a light value around the torch when they need to be there. Which is harder than it might sound. OR you can rewrite the whole lighting engine which would be horrid and likely impossible even with Reflection.