Just do the POH book speeds if it says to add for gust then do so but I would be suprised if it did.
There are two ways of doing the approach your method and point and power and both methods have there merits and both are correct.
You are flying a VFR approach not a Instrument approach so the PAPIS arn't really in the equation again its instructors making students fly SEP as an airliner.
If at any point during your approach your engine failed and you couldn't have made the runway its not a good approach. If it had failed short finals you would have been in the houses.