Yeah. I did admit it was a pretty dumb thing to say.
All those things are well within the purview of magic, and entirely appropriate to the motivations of the beings involved. They are all short-term one-off effects.
To feed a city of Drow with magic would require a massive effort on the part of the priests every single day... an effort that would appear to be totally out of character for chaotic and evil clerics of a deity who loves cruelty. It's possible, but it seems wildly out of character.
Yet if you don't rely on magic, then you have to posit some mundane means of feeding all those drow and all their slaves. Which means lots of drow shepherds keeping rothe, or their equivalent, and huge underground fields of mushrooms being tended by drow farmers. I find the whole thing incredibly jarring, not least because war in the Underdark then becomes not a matter of wiping out the enemy cities, but instead locating and destroying the food supplies for those cities.
So, I don't see quite how a society such as that described by the drow could come into existence. As far as I can tell, it's fundamentally flawed.
(What I can see working is if the drow were significantly fewer in number, lived much closer to the surface, relied on raiding for survival, and were considerably more desperate in their outlook. It also strikes me as fitting better - being banished to the Underdark doesn't seem much of a punishment when it means you get to be ultra-kewl and live in a luxurious metropolis like Menzoberranzan.)
None of that means I can't or don't enjoy the use of the Drow in the game.
Incidentally, I have exactly the same problem with the new BSG, which I nonetheless consider one of my favourite shows. There, humanity was abruptly cut off from their fields, in ships that almost certainly carried minimal supplies. Within a month, they would have been desperately short on the basic necessities of life, and the first time they got a chance to stop long enough to raise a crop was at the end of season 2. With no ability to forage in space, and virtually no chance to explore life-supporting planets, what have they been eating? And, in fact, their situation much worse than that of the drow - in BSG there isn't even anyone with whom to trade, since the only other power are the Cylons, who are hell-bent on ending humanity.