1. What cruft can I delete from Win10 to speed it up? I want everything gone that I don't absolutely need: Edge, IE, Wordpad, Notepad, the file browser if possible. All I want is a platform for browsing the internet, coding, and gaming via Steam.
2. How do I delete said cruft?
3. How do I make the user interface look less like shit? Windows 7 or XP is a good look, none of this pseudo-tablet shit.
4. How do I disable/remove telemetry?
5. How do I permanently and reliably stop automatic updates?
First, there's a difference between hard drive space and memory. Edge, Wordpad etc. are sitting on your hard drive doing nothing, you don't need to remove those. Insisting would be nothing but a case of OCD. File Explorer itself is, unfortunately, a part of explorer.exe itself. It's technically possible to replace the default explorer.exe, and in the past people have written alternative implementations to replace it with, but ultimate those have fallen by the wayside and explorer.exe remains king on Windows. You can use alternative file explorers, there's a few you can find by searching online, although I've tried them all and have been unimpressed.
Disabling telemetry is easy, all of it is accessible through the Settings app. Do keep in mind telemetry is entirely anonymized and is mostly overhyped as evil incarnate because Microsoft has the audacity to be
honest about collecting user information as opposed to literally any other tech company who outright lies about it or keeps it secret like Facebook and Google. Your privacy will not be compromised as long as you disable targeted ads in your Microsoft account. If you want to be sure, go into the Settings app, Privacy > Diagnostics, click Diagnostic Data Viewer, it'll open the Store app to download the Diagnostic Data Viewer. This tool shows you the entirity of the raw JSON that Windows and all Apps you download compile to send back to MS verbatim. There is nothing hidden here, nothing that insults your intelligence.
If you're still distrusting of the telemetric aspects of Windows 10, keep in mind Windows Error Reporting is the exact same concept, it collects a dump of crashed programs along with all of your computer's hardware specifications and sends it to MS for debugging purposes, and it's been in Windows since XP at least. And you can disable it like anything else.
I already posted a link to stop automatic updating:
https://seowsource.com/disable-automatic-updates-using-group-policy-windows-10/
Keep in mind I don't outright recommend using this. I use it myself, not to be a hypocrite. But running an unpatched system is not safe and not recommended. Use this at your own risk, as I am doing. Note it will still nag you to update through the Notification system, but it won't force you to restart or anything like that.
Please for the love of god stop thinking of Windows 10 as some sort of monolithic corporate monster. It is a technical system that can be learned and controlled just like anything else, including Linux, especially Linux. Windows 10 is trivial to use and control after learning even a little bit about the Registry and Group Policy. Trust me, it's worth learning. Not for privacy, Windows 10 respects privacy quite a bit, but it's really good to be able to properly administrate your system and actually understand how it functions.