Your sentences do have a negative feel, so at all is well used there.
At all used affirmatively (both in form and 'feel') has mostly died out, but it was there in the beginning, and does survive in some parts of the world:
Before the negative, conditional, and interrogative usages came into being, “at all” was used in affirmative statements to mean “in every way,” “altogether,” “wholly,” and “solely,” the OED says.
The dictionary’s earliest example, from about 1350, is
- I þe coniure & comande att alle” (I thee conjure and command at all).
The affirmative use of the phrase has died out in common usage, however, and now survives only in some regional dialects of American and Irish English.
A 1945 article in the journal American Speech says this affirmative use “lives on in Irish dialect and in colloquial speech in certain parts of America, especially after a superlative.”
The article, which gives
- We had the best time at all
for an example, says the usage was reported in Georgia, Kentucky, North Carolina, Oklahoma, elsewhere in the South, and the Midwest.
See more about the affirmative use of "at all" on Grammarphobia