I would be interested in how German law works to make this so, IANAL but pretty sure USA copy right law does not work that way. Modification for personal use is normally going to be 100% acceptable under USA copyright law. The DMCA Anti-Circumvention is one exception I know to this but it was and is a big deal for being an exception.
Running any software that then does anything with the same memory space (cheating software or, say, antivirus) is another, separate instance of copyright infringement on top of that.
But ask yourself, would business do this anyway? The answer is yes. Google needs a growth target and modeling app store lockin and fees is there.
Youre free to live in paranoid government land, but its an unnecessary abstraction. Its actually the EU and US rulings against their monopoly thats driving it.
Again, the paranoia is just drivel.
This is just what you'd expect any government that is either competent or greedy to be doing, given the technologies at play.
Calling it "thought crime" is, of course, a bit glib. But things like "we want to monitor the communications of every pro Palestinian university student so we can take proactive disruptive actions" are very real and not so hidden desires and sentiments of modern Western governments.