Thank you Flavio, this is helpful.
Have you faced any other challenges or any other problems after installing Postgres?
No problem related to software installation whatsoever, you'll need to take care of the same points as any Postgres usage and some cloud specific care like replication between geographically separated instances (what they call availability zones) and disk performance.
I suggest you to try it and read a bit, you'll find a lot of feedback from people that already did it on the internet and AWS documentation is key when dealing with their hardware specifics. I only learned how to do some stuff their way when I tried, even with AWS premium support at hand. Because every database is different.
Questions on this list are better handled when you have a more specific question with a problem you're experiencing (like your first one) and the hackers list is more aimed at Postgres development, post user questions on pgsql-general.
Flavio Gurgel