1. It seems you have likely a broken shaft seal
on your port SD. Once this is broken it will leak salt water
into the drive oil casing and will turn your normally clear oil milky white. Chocolate - not sure where this may come from? Concerning this, after changing your saltwater infested SD oil, you will need to continue to monitor
the oil for cloudiness to avoid any corrosion
. You may have to change it frequently until you get the opportunity to change your shaft seals
(haul your boat). We had the same situation while in Madagascar
(fishing line around shaft and broke the seal) and had to pull the boat
out in Zululand. Its an expensive lesson.
2. Yes, you will get near 2.8L out when you drain from the underside of the SD. Taking oil out from the drain tube or via the filler cap, will not take all your oil out as the tube doesn't reach the base of the casing. This is fine for a few oil changes but when your on the dry then drain the oil from the plug
on the underside of the SD. You have standard SD's without extensions i.e. 2.8L.
3. See above. I have sucked it out from both the filler cap and the hose next to the filler cap. I use an electric
oil pump but as mentioned, you will only get a portion of the oil out. A liter or so will continue to sit at the base of the SD casing..