I use a wireless charger at home with my Nexus 5 but when I travel I'd like to use the Nexus 7 charger for both my phone and tablet. Will I "burn up" my Nexus 5?
USB charging is a standard, you can use any USB charger with any USB compatible phone. There are some chargers that are designed to be used with iPhones that support a non-standard protocol that speeds up the charging of iPhones. With older versions of Android these chargers performed poorly, however as of 4.2 or thereabouts Google figured out what they were doing and now those chargers will also work at full rate with Android phones.