Even if you could block their ability to delete accounts couldn’t they still simply delete every post from the person? Or continue tampering with them? Especially if you already don’t want to check the logs, they could simply come in and wipe out as many back posts as they want constantly.
Not to mention silencing, anonymizing, suspending, trust level limiting, merging and splitting topics, there’s essentially countless ways to cause a severe amount of calamity that you’ll either 1. Remain unaware of until it will require a lot of work/reset to fix (at the cost of losing progress) or 2. something you’ll have to constantly monitor. Neither of these sound fun.
The option of just removing all powers one by one circularly brings you back to don’t have them in the first place. If you can’t find someone to trust them IMO your second best option is to find something with the very least amount of power required, and then try to add on whatever specific thing you need them to be able to do vs. giving them a ton of power and trying to block it piece by piece. As mentioned looking at Category Moderators, or Trust Level 4 options. First identifying what you NEED them to do, instead of what you DONT want them to do