https://aws.amazon.com/free/free-tier-faqs/I don't think any KYC is needed, other than the credit card and billing address should you go over your free limits. They just sell services - they don't do anything with crypto.
There are no limits - it scales instantly as you need it. You only get charged for what you use. Free tier can have you run a web service and 20GB relational database 24 hours per day.
You need a billing address at all times even when just using the free tier and you got to list one at sign-up. Also while it's a generously long free tier covering 1 server (t2.micro if you want details with 2 cores, 1GB memory and a 30GB ssd disk) for 12 months, these resources are quite constraining for web servers especially the memory.
Lightsail and Elastic Beanstalk both use EC2 internally which charges an egress fee (even during the free tier) if the amount of upload traffic exceeds a certain number of gigabytes per month, so my take is that hosting with the above mentioned free server is only suitable for small sites.
Of course there are thousands of people and orgs hosting on AWS and it's possible to rent a decent spec server that can handle enough traffic for medium sized sites for like $27/month - the t3a.medium with 4GB memory, or if it's only going to run linux web hosting software it'll probably work on their ARM64 servers as well so if that's the case I recommend a1.large at $37/month which has crazy fast network speeds with a 10Gbit line and that server's CPUs aren't throttled at 10% or 20% per core or at some other crippling rate like the t2* and t3* servers are (although you can turn that off it's not worth the price increase. Network speed is also throttled from the advertised rate and can't be turned off).
Basically if you're just using common software then their ARM64 servers have a better price/performance ratio and aren't throttled or limited in any way. T2 and T3 are their budget servers for running smaller things on.
The best part about AWS is the storage is billed separately from the server itself so the 30GB ssd I mentioned above is billed by itself. This means you only have to pay for whatever server type suits you and ride on the free tier storage you get, it's more than enough storage for web hosting anyway, each extra gigabyte adds +$0.1/month to the billing statement and the SSD ensures performance isn't throttled by slow disk read speeds. The database is also billed separately so you get a decent DB size for free as well.
And of course run all your servers in us-east-1, it has the cheapest rates of all regions. It also has more temporary outages than the others but for small projects they shouldn't be a big problem.