I run a number of Amazon Servers which is supported by myself and some of my developers.
However we aren't always available, and if I am to offer hosting to clients, I need to be able to provide access to tech support when they need it
For this to be economically viable, it would need to be an 'as required' service as I couldn't afford 24/7 staff.
But if it was available 'on call' at least during Australian Business hours, then perhaps it would work.
Skills to support a Linux server on AWS? Basic tasks would be;
periodic monitoring of server load
restarting services as required
rebooting the server as required
troubleshooting a service
Advanced tasks may/may not be required because they are less time critical, and could be referred to myself and team. Advanced tasks would be less required but may include troubleshooting
an application e.g. Drupal
a database issue on MySQL
email marketing software
other server software of configuration items as required