Response to Q3: I will take your word for it!
Response to Q9: Nice idea, but… a solution exists even if Alice failed to do this. What is it?
Response to Q8: Correct answer, well done.
Another solution for Q3: On a sunny day, measure the ratio of the thermometer’s length to its shadow’s length. Use this to estimate the building’s height based on its shadow’s length.
P.S. So far, at time of posting (≈8:45am on 27/10/2023), correct solutions have been posted for Questions 1,2,3,4,6,8 and maybe 5 & 9. Keep up the good work!