Use Mastodon or any decentralised platform responsibly is the way, in my opinion. If you can run your own instance, that will likely lead to better control over your data but does't mean others servers won't see it. that is the nature of these platforms by design.
Don't put trust in anyone for it. When you make an account, go through the settings and adjust them based on what you are comfortable with. Use an alias name and email, of course. opt out of search engine appearances, or even social graph. Hide people you follow and that follow you. Adjust the settings of each post based on what it is as well.
End of the day, you will need to trust the person running the instance to do good enough management of the infrastructure. Use a server with active and transparent admin and it's not too large to manage for them.
You guys are still using the same email?