I doubt people want to keep their styles secret but I could be mistaken. It is more likely that my styles and POI icons, or someone elses, are not ones you would particularly care about. For example, I have special POIs for milestones (common in Thailand), and assorted trees (trees common in Thailand) and style rules that test for them and place them on my maps. In addition, everything I'm developing is in a continual state of flux — I'm changing rules and icons all the time as my ideas about what's important (or fun) to map change.
Would my styles and TYP file be of any interest to you?
If so, merely say the word and I'll post them in my Dropbox and send you the links.
Best
Dave