The fuel level just flashing usually means the fuel level sender wire isn't plugged in under the tank.
Turn signal stuck on sounds like a switch fault. Give it a squirt of contact cleaner and a few jabs of the button. Maybe unplug the switch loom to make sure it's the switch and not downstream of that. Then replace the switch. they're cheap as shit on ebay.
Neutral light, try it in the dark. It's really dim and nearly impossible to see in the daylight. Othewise unplug it from the switch, earth the wire and see if it lights up. if it does, replace the switch. If not, wiring fault or dead LED in dash. An instrument guy can fix that.
Tail light, probably hopefully just a broken filament in the dual filament bulb. The brake light filament lasts for ever but the tail light one dies every few 1000 miles from the vibration and being constantly lit.