I have both paid and accounts with Proton and I have no idea what you're talking about.
Yes, they make it clear they offer suite of services, and notify you of new services being launched, but my screen isn't saturated, and my workflow isn't negatively impacted.
...and they are nothing like Google in terms of self promotion, to say nothing of Google's business practices.
No, yes, maybe, but probably not.
Also, only do this if it's a passion project for learning, because the odds that it works out the gate, and doesn't require multiple repurchases, are very slim.
The odds that you never quite get it to work right, or at all, very high.
If you're sure you want to do this, start by reading the technical documentation to get a grasp of which parts might, or should, work together, and how. Do this before making any purchases.
If that doesn't sound appealing, then buy an "digital signage" or "enterprise/business class" TV, or find a dumb consumer TV, new or used.