i would focus on one problem at a time, first the fuel gauge, take the sending unit out of the tank from the top inside the car under the rear carpet toyo was smart and put in an access door for us. 3 screwes on the cover and 3 or 6, 10 mil bolts for the sending unit. pull it out carefully and manually move it full range while someone watches the gauges with the key on. mine had varnish built up on the reistate wireing wrap that the float arm rubs against. once i carefully scrapped the varnish off, the arm made contact with metal again. 2 years now and it still works fine. make sure the float is still sealed with air and (floats) and not half full of fuel. see if that fixes one issue? and go from there...
