(i) pretty much underlines my point about the things people choose to spend their money on not necessarily being what's best for them. And in the short term it's not an inexplicable phenomenon because cheap tobacco probably does provide more pain and stress relief than slightly better nutrition.
(ii) is partly because surveys like those you've posted accurately represent people tending not alter their habits of smoking cheap cigarettes (or frowning on tobacco) after receiving a sudden windfall; there's a limit to how much one can smoke and stockpiling makes no sense when for people who don't even have a waterproof roof. But it's also because poor people are smart enough to realise that people quizzing them on their lifestyle and unexpected windfalls from foreign donors aren't unrelated, and the natural response is to tailor responses to what they think the foreign donors want to hear, resulting in any increases in spending on cigarettes and alcohol (whilst likely low relative to increases in spending on roofs or microbusiness investments anyway) being systematically underreported.