But then I'd have to manage and maintain a server. What if I don't want to be a server administrator?

It's not that time consuming. Digital Ocean will set up LAMP for you (or even install Drupal or Wordpress if that's your thing). Secure SSH, set up your app, set up monitoring and leave it alone.

I want to move from shared hosting. Looking at DO. Have scores of sites to migrate. I use NameCheap for domain reg and point to host. Can I host multiple domains at DO? How does it work for multiple sites?

Would setup be something like:

1. Get DO account 2. Install LAMP 3. Setup multiple sub domains in DO? 4. Create site directories in DO and copy site files into them? 5. Point domains to sub domains?

I use DO and not Linode but would like to note that Linode is more expensive only if you use DO's $5 option. Starting from the $10/month option, they are very similar in pricing with Linode being cheaper in some respects.