Re: oil float switch
I don't know what was going on w/ your earlier problems, because I don't believe the oil-related alarms cut back the RPMs. That would be an overheat.
If you're getting the no oil alarm, I can't see why that would related to the float switch in the tank. A bad float switch would give you a Low oil alarm, a different sensor than the No Oil alarm which is at the pump itself.
Have you read this article? It's a good primer on the system. continuouswave.com/whaler/reference/VRO.html
If you're getting a no oil alarm that goes away when you throttle up, and your VRO/OMS pump is pretty new and in good shape, you then need to check the oil supply system because something is restricting the oil flow to the pump. Look from top to bottm, from the pump to the tank. Look for possible air leaks, any kinks or restrictions in the oil line, inspect the line and tank pick up.
Also, if you're uncertain at all about the oil supply, run premix 50:1 in your fuel tank until you get it straightened out. That way you wont' harm your engine for lack of oil. And, then do a oil consumption check - mark the oil tank at the level of the oil and fill your fuel tank. Run 5-10 gallons through it, and measure exactly how much fuel and oil you've used.
By the way the intermittent alarm Rick was mentioning is for the older VRO/OMS systems before the system check came on line. The older system didn't have a light telling you which alarm was sounding, the pattern of the alarm told you. Your system has an alarm accompanied by a dashboard light that tells you what the proble is, right?