I would check with the manufacturer, as only the OEM can warranty your furnace. I don’t think amp draw is really a “necessary” thing to check. Maybe confirm the set screw is tight on the blower, but if it isn’t then I think you would hear some noise from it. Obviously change the filter regularly, although a dirty filter will actually work better as it has more surface area. I think I might put an electrostatic filter in myself to cut down on the amount of dust.