I think I need a combination of 2 devices, a high quality USB one that can accept a mic (or multiple mic) input and act as an ADC, and the microphone itself. i dont see any other way to get all the usage listed above without going this route unless I scratch the headphone testing part or unless the mic has an external microphone option.
I think the mic definitely needs to have both stereo and omnidirectional capabilities but again, i think this depends on if I get 2 distinct devices or one device that can do everything. I havent ever dealt with this stuff though so I have no idea what i'm getting into.
I dont really have a price range as of yet. If it is a worthwhile investment and I can record school lectures and stuff with it, and if it is pretty accurate in recording the audio signals it receives, i'll be more inclined to save up and splurge on it as a proper investment as both a research tool and a learning tool (some teachers make you buy hundreds of dollars worth of textbooks and then never reference them, choosing to give tests based entirely off of lectures and notes). However, if this is something that any decent mic plugged into the line input of my laptop can do (highly unlikely, its super low quality, i think) then i'd rather get a decent audio-level mic capable of long range and just live with that. I dont really know what kinds of realistic prices i'm looking at either, obviously I can go out and spend 10 grand on something like this but I feel like this sort of thing shouldnt cost more than 200-400 bucks if I really get some pro-level stuff that is way over my needs level. Perhaps i'm wrong.