The second part of my question is about mixing hardwood with the tile we currently have everywhere. Would it look funny to have some rooms with hardwood floors while leaving the tile in others? Or is it an all or nothing deal, meaning we'd have to demo all the tile and replace with wood and new baseboards (currently we have tile base boards), or learn to live with all the tile?
ANSWER - There is nothing wrong with having some rooms with hardwood flooring and other rooms with ceramic porcelain tile as I do in my house. You need to be careful about the transitions from one floor material to the other as they likely have different thicknesses. So you need to install thresholds or reducers where it transitions from a thicker material to a thinner material. You also have to caulk/fill the transitions joints between these materials with a resilient sealant/caulking that meets ASTM C920 that is normally a silicone or polyurethane sealant to mitigate the expected differential movements between different adjacent materials.