Raymundo:1246996780 wrote
If I use namespaces to organize content, the namespaces won't be visible on my home/start page, right?
No, if a link appears on the home page or not is entirely independent of its target being in a namespace or not. Whatever you link from your home page will be visible there. If you don't link it, it isn't. (The same is true for simple pages in the root namespace: If you don't link them, they will only be visible in the index.)
Raymundo:1246996780 wrote
My question is do I have to use namespaces to organize my content?
No.
It highly depends on what the content of your wiki is and with what you and your users are most comfortable with.
In many cases I'd recommend using namespaces. But sometimes it can also be better not to use them. Wikipedia at least works well enough without them.