AWS win08 server ami iis subdomain domain dns entries setup and configuration

I've inherited an AWS infrastructure where there are a number of win08 webservers running IIS set up. Each webserver hosts a number of sites.

I'm at a loss to unravel the configuration setup and need advice.

None of the webservers are attached to directory services, there is no vpc either, I've been told that the dns information is in Route 53, but on inspection see no setup what so ever.

a number of customers have raised an issue where by they want to be able to enter the just the address without the www subdomain into browser address bars. All the sites are configured in IIS with the hostname in the format of www.[domain].[tld].

I have been told it's not possible to point the "A record" at the "site" in AWS and it must use "cnames".

I'm confused by what I've been told, these answers appear to give me some information but aren't AWS specific.

These questions give me some of the answer I think I'm looking for

HTTPS redirect from root domain (i.e. apex or 'naked') to 'www' subdomain without browser throwing up?

Correct DNS setup for custom domain with subdomains and CNAMES pointing at them

DNS Configuration for domains and subdomains to point to single IP

but at this moment I'm unsure what to do as the set up looks rather fragile.