Yeah, I just looked and several items are on backorder.
It's not a big deal; either wait for them to be back in stock, or just make an educated guess for a suitable replacement. Esp for caps/resistors; just find a replacement with the same voltage rating (or higher), the same component value, same footprint, and same wattage (or higher), and you should be fine.
The LEDs; you can replace with anything that fits; they're only for indication.
The CANBUS protection IC isn't 100% required; things will work without it; it's just a safety device.
The analog switch can be omitted, but you'll have to jump the 3.3v rail from vreg to the rest of the device, and then you just won't have the ability to cut power to the module (via software, via the switch but I don't think it even had code yet anyway).
Just use common sense...
NC, USA