And you can always change career path if something else is seems more interesting at a later time. I did at a relatively late age and know of plenty of other people who did the same. It's never too late to try something else if the first thing doesn't works out.
If you care at all about privacy I wouldn't reccomned M365. Because: Schrems II and MS use your information for their own purpose, and in effect is not compliant with fx GDPR.
Don't know precisely, but hear from time to time that Microsoft is notorious for not patching in time in many cases, leaving vulnerabilities for months and sometimes years. I am pretty sure that MS just kinda gave up on the vulnerabilities MimiKatz exploits, so if the bad guys are on your network and you use MS infra it's pretty much a question of time before they get admin credentials.
Yes, often overlooked. And, I hear, almost impossible to selfhost these days without a degree in CS, because "we block all non big tech e-mail providers".
As far as possible I try to avoid:
All things from big tech because privacy, see Schrems II and their terms on use of personal information for own purposes
Non Open Source tech because privacy or other malicious functions
Tech that are prone to planned obsolescence because of special batteries etc. and can't be fixed with for example a custom ROM on Android