1.) not part of the current Studio functionality. You can try to use some 3d label and change dynamical their location but in it will be difficult to create some leader lines to the components.
I think this is a vuforia application and is not studio but not sure . It possible that this is some special customization for this large customer.
2.) and 3.) you need to check the eye vector so you can deside the camera position and then do the correct action (display , move, hide)
4.) I believe that this video / the functionality shown there is a result of long work process / investment - some weeks or months so that I do not believe that some ony could answer this question in few minute . you can try to contact the customer and try to get some detail or contact the PTC professional service to help you / in case that the customer application /respectively customization was developed by PTC.
For example, the highlighting is some TML Widget shader definitions. Also there is list of the components extracted ... etc. .We can discuss here particular features but not all in one