yes, as long as the detector's settings can find gold, it will find white gold.
most likely no. you are going to have other metals all over your house such as supports/nails/screws/wiring/plumbing. those things will all set off the detector as well, every time it gets near one.
most likely no. you are going to have other metals all over your house such as supports/nails/screws/wiring/plumbing. those things will all set off the detector as well, every time it gets near one.