Thanks for these reports! I recently discovered a bug myself, so a to-do list is already started and I'll add these reports to it. I'm glad you're enjoying the game!
I just realised what that last bug was. Starter weapons in shops (slings, daggers, staves) are always pre-identified, which is why you can't identify a sling you bought in the shop - it's already identified. All weapons, shields and armour have a chance of generating with enchantments or curses. But it would be unfair to let you waste money on a starter weapon that's cursed, which is why the shopkeepers pre-identify them.
If you have blade skill and can afford a sword, though, you're taking a gamble on buying it. And also slings, daggers and staves found in the dungeon are not pre-identified. So if you have a plain sling and you find another in the dungeon, it's worth having it identified to see if it has a useful enchantment.