Hello, Elle!
No, the "e" for drug/ecstasy has no connection with the "e" in Whiskey.
And "crack" is some kind of drug, too.
It is quite a straightforward methodical clue, but not everyone would link whiskey to the phonetic alphabet.
I used the phonetic alphabet for years when I was working, so it jumped out at me fairly quickly.
I thought "tinny" was a good one.
I learned about "tinny" in the same book where I learned "Hill's Hoist" and "arvo"!
Yes, slightly overthinking, Elle!
No harm in that, and I find I am always learning with crossword puzzles.
You will be likewise, I'm sure!
You learned a little bit today!