Two servers replicating data are not ideal in my eyes - I would recommend you review 101: backup what and why (not how). In my eyes most requirements are better solved by solid backup rather than HA. we had some discussions about high-availability here likely you find interesting insight there.
this is not true. MS is definitely doing a lot to keep your data available but this doesn’t help if entire service fails or some crazy person applies sanctions on your country or your business. But yes this topic far beyond of threat model and capability of most people.