A:AnswerYour iPad has “Find My __” already built-in, wouldn’t need one for that” as far as the 2nd half of your question… it IS rather small and easy to hide.
A:AnswerIt can be put anywhere you please even tho I would recommend you place it in a rubber case first and put an adhesive on the case to affix it to your PC case
A:AnswerYes, as long as another iPhone or iPad is within range it will continue to ping devices and update its location. Once you get closer you can have it play a sound to audibly track down your tag.