So... first of all the constraints for this project were pretty unusual - I didn't have time to work on it but had to respond fast because people actually relied on this site (which is crazy! why would you do that??).
Anyway:
1. I used Azure web app, azure queues and servicebus - these were amazingly helpful and allowed me to scale up in a manner of a couple of hours (most of it was adjusting my code for scalability). It would've been much much much more complicated if I had to install and configure it all by myself.
So Azure proved very handy and also ended up costing me $14 total... The only problem started when Pikud HaOref blocked their API to all IPs from outside Israel... Then I had to find "creative" solutions to workaround it.
2. I had heard about WebJobs before but decided I didn't want to learn a new thing for that manner at that time. WebBackgrounder worked great and did exactly what I needed from it so I'm pretty happy with that decision.
3. At the beginning I had to change the Area DB all the time and this caused me lots of trouble, especially alerts being missed. So a solutions that's "always on" would have been a much better fit. In addition, after a while I wanted to add more data about each area but eventually decided not to because I didn't want to start writing back to a text file and didn't have the time to migrate to a DB...