07' Mercury 90 HP 2 Stroke Advice

[05crestliner]

New to the forum... just purchased a 05 Crestliner Pontoon with a 07? Mercury 90 HP 2 stroke. Hopefully some can educate me. The engine supposedly has low hours and not run much. Seems to smoke a lot thoughts are it needs to be run. Is there preferred 2 stroke oil? Owner told me when starting the engine to push the key in for a bit then start. Does pushing the key in activate the choke?s on the carbs? The tach and charging gauges do not work any suggestions? Is there any common characteristics of these engines?

Thanks Tom