Cannot resolve method 'renderHoveredToolTip' in Forge 1.16.5 and 2 more issues

[Mrlowyaw Mrcreativschik]

I was trying to backdrop some code from 1.14.4 to 1.16.5, but I found a lot of Issues, trying to compilate. Mostly in making GUI

1. Cannot resolve method 'renderHoveredToolTip', when in 1.14.4 can be found 

@Override
    public void render(int mouseX, int mouseY, float partialTicks)
    {
        this.renderBackground();
        super.render(mouseX, mouseY, partialTicks);
        this.renderHoveredToolTip(mouseX, mouseY); //<--- Here
        // this.signTextField.render(mouseX, mouseY, partialTicks);
    }

2. Methods from net.minecraft.client.gui.AbstractGui like "blit", "fill", require MatrixStack, where in 1.14.4 it doesn't require. If I write:

private MatrixStack matrixStack = new MatrixStack();

Would it be enough?

3. Super.read requires BlockState(). But writing "new , where in 1.14.4 it doesn't require." compilator still mark this as issue "Expected 3 arguments but found 0", where in 1.14.4 it doesn't even require BlockState().

public void read(CompoundNBT nbt)
    {
        RoadStuff.LOGGER.debug("read nbt");
        super.read(new BlockState(),nbt);
		<...>
	}

What should I white here?