Advice on cleaning the travertine tile.

I have travertine tile in my bathroom,

1. What should I use to clean it with ?

2. I have a small hole in one of the tiles, do I need to replace the tile or can I fill it with a product?

3. Was it a good choice to have selected Traveltine for my bathroom floor?

Lastly, how often should I seal the tile?

Thanks,

Beth