1. That old lady sounds awesome. I hope she's using that power's potential.
2. Is that an S5 or an RS5? I assume it's the former.
3. I think that would be a great acquisition for the reasons you mentioned. I have two family friends that have them and have very few bad things to say about them. I test drove one as a part of my local BMW dealership's test drive event to compare similar cars to the 435i X-Drive. I thought the S5 held it's own well against the competition, even though I preferred the 435i.
Let us know what you end up doing.
+1