Staged publishing on Azure is limited to 5 slots, not 2. But you are correct, it doesn't scale out to 200 slots. However, in Azure, you pay for the first slot, the additional 4 are free, while the same isn't true in AWS.
As for SQL performance in Azure, I can't make an exact comparison, but you always have the option of running your own SQL server if you don't like the SQL Service. And even the cheapest Azure plan gets your point in time backup/restore, although the amount of time increase as you change service levels (basic - 7 days to premium - 35 days) and the cost of a P1 database is roughly half that of a single "db.m3.xlarge" instance on AWS ($465 vs $968.40), and the price gets worse from there. Multi-zoned databases on AWS are basically full cost, while on Azure (called GEO-replicas), they become cheaper. Then tack on some more if you care about provisioned IOPS (which comes free with Azure, as all tiers are allocated that way), and you've quickly turned up a huge bill for the same performance from Azure.
As for AWS RDS being the "full" version of SQL Server, I suppose that is true if you only need the functions in SQL Standard (Amazon doesn't offer enterprise). Unfortunately, we use features only available in enterprise (like being able to enlist indexed/materialized views in queries automatically), and AWS RDS service doesn't support that while Azure does -- so your "full" version is less "full" than than your "not-full" version of Azure's SQL service. Amazon's RDS is limited to 1 replica, vs 4 in Azure (we don't actually use this, yet) as well.
As for the "slammer" idea, that is quite funny, when the exact opposite would be true assuming there still exists vulnerabilities in the Service locator service. Azure likely doesn't use the same code, while AWS does, so they would be more likely to be hit than Azure *IF* another vulnerability exists, but good job bringing up a 13 year old irrelevant vulnerability into the discussion.