AWS RDS Postgres and the DBA: Which/how many aws permissions/access do we really need?

So, I'm looking for advice here. Can anyone recommend a list of
useful/required AWS RDS permissions for a pro-active DBA? We are taking
custody of a set of databases that will need sane backup and recovery
plans; table partitioning; undiscovered postgres extensions and we don't
yet know what else.

RDSADMIN is out of the question, even though it would be the one-stop shop
for managing the clusters and databases. But, unless I have to, I do not
care to administrate by trial and error ((tripping over each mine in the
field.)

Any advice would be appreciated.

Thanks,
Gus