It seems like you're worrying yourself too much!
Satisfaction is guaranteed! You'll get a sun tan and will feel the warm waters on your skin!
If you're living in Grand Baie, I would advise you to try the Western Coast, and go down South via Black River ranges and Chamarel (more than 7 coloured earth).
Next time you can try North and Eastern parts. There are really interesting places to see. Your hotel will supply you with a proper map and all the information so no worries about that.
Things you definitely need to see
North: Pamplemousses Garden
West: Chamarel coloured earths, Chamarel Falls, Black River Ranges, Rochester Falls, Tamarin, Le Morne Brabant.
South: Souffleur and Roche qui Pleure (Breathtaking Cliffs), L'aventure du Sucre (the sugar factories and liquor making)
East: Belle Mare, Waterpark, Ile aux Cerfs
This link gives you a description:
One last thing: Don't bring too much clothing. You can buy all types of clothing at bargain prices in Port-Louis Caudan Waterfront and other towns if you're visiting!
Hope this helps