Give the lad a break. We all started our passion somewhere. What's wrong with everyone?
This.
There are certainly no shortage of armchair aviators willing to spend their time on pprune (doubtless in their pants with a half eaten 2 day old pizza beside them) waiting, eagle-eyed, for opportunities to stick their topgun shades on and demonstrate how cool they are.
You should all be ashamed of yourselves. I earnestly hope none of you are instructors.
OP:
VFR is "useful" because we don't all have an IR. We all learn to fly VFR first because that's how you learn the fundamentals of how to fly - attitude and power, lookout, pilotage and the other stuff that you later build on when you learn how to fly IFR.
The GPWS I'm not sure about, I don't fly airliners, but I do think it should automatically disarm under the conditions you described, perhaps a glitch in the sim, or a misconfiguration by the instructor.
TCAS I believe should be automatically inhibited on the ground, so it would be normal not to receive a TCAS TA or RA on the ground.