Kori,
Your creativeness is commendable. For me, if the three bonus questions are important, I would just make them part of the graded quiz (or ask the questions without grading to challenge the students knlowledge). Students will come to expect "extra" in everything, and in the workplace, there is no extra credit. Very small adjustments at the end of a course seem reasonable, like a bonus question on a final exam, or dropping the lowest quiz score (in a class where are a lot of quizes). This shows some consideration for having a bad day, or recognition of knowledge above… >>>