Things I learned about hardwood and tile

While my guy that's going to lay my hardwood and tile was at my house the other day, I picked his brain for some information and here's a summary of what I found out:
1. Hardwood should be brought into the house and left for 2 days before putting it down, so that it can acclimate to the temperature and humidity of the house. Wood changes size with changes in surroundings, it needs to get used to the house's atmosphere before installing it.
2. Is thick tile less likely to break than thin tile? It doesn't make any difference how thick or thin the tile is, the important thing is that it's layed on a cement board (Durock is a common brand). The cement board is what the tile are glued to. Houses expand and contract with temperature changes and the cement board keeps the tile from moving while allowing the house to move. That is the single thing that keeps tile from breaking in nearly all cases.
3. If I have an area of floor where the subfloor is damaged, can this be repaired to have tile laid over it? Yep, quite doable.
4. How do I tell if my bathroom floor is water-damaged and needs replaced before laying tile? If the floor is soft OR if the plywood subfloor is wavy or raised, compared to the surrounding floor, then it's damaged. Plywood usually gets wavy or elevates with water damage.
5. If I have hardwood, should I have tile at my entrance foyer? Yes, it's recommended, because people bring in water and trash on their shoes. The water will damage hardwood over time and the trash will scratch it over time. It's best to have tile where you enter to protect the hardwood.
6. Does it cost more to install narrower pieces of hardwood instead of wider pieces? Most people do charge more for narrower hardwood, as it's more labor-intensive to lay it. (more pieces = more time)
7. You might have to cut off the bottom of some doors when going from carpet to hardwood or tile, as the new flooring might be higher and thus interfere with the swing of the door. (it's easily done, however)
8. What about grout? Does it need sealed? Standard grout (Tec is a common brand) does need to be sealed, there is a spray sealer that you just spray over the grout lines, you do not have to remove it from the tile. It makes the grout waterproof and prolongs its life. They do make a epoxy grout that is totally waterproof, but most people only use this on countertops or in showers. Epoxy grout is much more expensive than standard grout and has to be applied wearing gloves.
9. Should I turn my leftover hardwood and tile back in to get money back at the place where I bought it? NO, don't do this, you may need matching replacement boards or tile in the future, keep these for possible replacements.