I haven't flown in for a couple of years, so if someone can give you more recent information than me, then listen to them. The strip is rough but not too rough for a 182. Forget the extra passengers for the first trip and keep the aircraft light. Don't believe the published distance of 400 metres. The SW end is (was?) very rough with many rocks so not all the length is useable in my opinion. Best go on a day with a strong SW wind ! Keep the gap in the wall between the two fields in view on short final because you loose sight of it when you land (strip is humped) and you want the gap in the stone wall to appear in front of you during your landing roll. Similarly for the take off; you can't see the gap from the "24" threshold, but you need it to be in front of you because you are likely to still be on the ground as you pass (hopefully through) the gap in the stone wall.
The other things to watch are:
Avoid the dark clumps you can see on short final. When you walk the strip you will see that they are very dense vegitation of some sort, possibly matted together. I kicked one clump to see how hard it was, and it hurt my foot. It would have hurt an aircraft wheel a lot more.
Unless things have changed, there are no pilots on the island, so no-one can really give you the sort of information you want on the state of the strip. Do a low pass first and decide where you are going to put the wheels. Walk the whole strip before your take-off run.
I am assuming you have got the necessary permission from the island.
Good Luck, its a fantastic place to fly into.