Remember that the land is the background, so you want to be cutting through the water to reveal it as the island. That's where the Color Key is to enable cutting.

If you use one of these two drawing tools you should be able to draw your island without any trouble, as long as you haven't significantly modified the way the sheets and effects are ordered and set up.

Yes. It's easier if you haven't already registered the product yourself, but if you have all is not lost - you can contact Profantasy from this page to get the registration transferred to the recipient. Remember, though, that a licence for an annual cannot be split into the different issues.

Plenty of people have, but not me. I also tend to design new styles more for screen appreciation. They aren't particularly printer friendly, though Profantasy have printed a couple of my example maps for display at Gen Con. They turned out really well, but were probably quite expensive.

@camilodiezr The Cartographer's Vault bundle contained some lovely maps drawn by a range of fantasy artists (including Alyssa Fadden), either in other apps or by traditional means. Those maps are not included in the current bundle.

@ZigZaw The help files are sadly not in good condition, but the User Manual has all the basic information in it. You also have the Tome of Ultimate Mapping in that bundle which contains nearly everything there is to know. I recommend using that only as a reference manual, though, since I don't believe anyone has ever managed to 'work through' it's 750+ pages.

If you import a symbol at a scale of 20 pixels per map unit, it doesn't make any difference what the dpi is of that image. It might be 72 or 600 dpi. It really doesn't matter, because it will be 20 pixels per map unit in the map.