1. Every feature needs a feature guid, it should not be random across installations, it should be the same across installations this is just an easy way to generate one but it is arbitrary.
2. Personal preference.
3. If a feature instance is enabled for MyPage as a webpart in module settings then when it renders in MyPage, the WebParts all get a title bar so the title control is redundant. When runing in MyPage the RenderInWebPartMode setting is true so it hides the module title control. The ModuleTitle control is strictly a convenience to make it easy to add a consistent title to different features, and to have a way to hook in edit links for a feature but you are completely free to leave it out and do your own thing. The if statement is just a defensive check to prevent errors in normal conditions its probably not needed.
Hope it helps,