Photo Etched parts bring a better sense of realism to the kits. Things like railings, radar dishes, doors, stairs, etc are all MUCH more realistic compared to their injected moulded counterparts. Take a look at my Enterprise build for pics of a ton of photo etch parts installed and in progress.
http://cs.finescale.com/fsm/modeling_subjects/f/7/t/148419.aspx
I’m building that exact kit you have once the Enterprise is finished.
I use CA Glue in varying thicknesses (superglue) and apply it with the tip of a pin.
I use primarily Enamel based paints for everything including photo etch and it adheres quite well. If your paint is Tamiya Acrylic, I have zero experience on applying it to anything other than plastics.
Mr.M