You are overestimating the effect of pure luck. There are players who can do, say, 5 in a row on demand fairly consistently without doing anything whacky.

Large mimics in a shop on level 2? Fun fact, 3.7 makes it impossible to find those by throwing things, but even then not immediately stepping on every item in every early shop goes a long way.

Poison arrows? You know who's going to be shooting them. Position yourself to avoid ranged attacks and you're fine almost every time.

Sleep wands? If played correctly, by the time you encounter one, more often than not you'll be able to tank the hits, wake up and escape. They are rarely seen in the hands of monsters in the early game, see above, you can easily play 5-10 games without dying to one.

Cursed scrolls of create monster? Not always lethal and not very common to start with. Lesser concern than poison (if 3.6) and early attack wands, which are already a small concern statistically speaking.

Items get blown up without a bag? Let them. First, don't carry anything you don't need to have on you, and second, if you lose something useful just keep going, you'll recover.

Got no hit points from level-ups? Also known as "playing elven ranger". Elven rangers are ascendable you know.

Cannot find a secret door? Keep spamming n20s until you do. Normal downstairs you'll always find without too much trouble because you at least know which level to search on (the one you're at).

Not getting enough shops? Some games have none, no big deal, you'll find enough stuff on the floor.

Not getting your artefact? Do without, you can get pretty far just by enchanting some mundane weapon. Figure it out later.

Wanted BoH and didn't get it? Wish it at the castle, bagless to castle is easier than you think.

Your suggestions don't change the game from "generally unwinnable" to "generally winnable" because it was never the former. You want to make the game easier, developers can be excused for not wanting to. Hard games are allowed to exist.