The rice solution is a complete myth. It doesn't work and never has. Open it up and try dabbing water away with a clean rag. After that, try cleaning with Ispropyl.
I got this from Eassus. "Upon the 'Preparing automatic repair' window, press-and-hold Power button 3 times to forcefully shut down the machine. The system will enter boot repair page after 2-3 times of reboot, choose Troubleshoot, then go on to Refresh PC or Reset PC." Of course, some data may be gone, and you may come across some problems but you can read the entire article here: https://www.easeus.com/resource/fix-preparing-automatic-repair-loop.html
This means that you tablet may have come across malware or viruses that it cannot handle. If your tablet is rooted, it could also mean that your boot loader is unlocked and can cause problems. Both of these are nothing you want to see. Try booting into safe mode and deleting any shady files or apps. If it's rooted, lock your boot loader. If all else fails, factory reset.
It's not the obsolescence that screwed it over, that only makes it !&&* to buy an obsolete product, but you already have one. It's probably the display, there are quite a few on EBay.
Probably broken. Take those keys off the board, see if there is something you should clean off it. Whether there is or not, clean it with SMALL dabs of Isopropyl with a QTIP. If it doesn't work, send it to Apple.