I'm my mom's go-to person for assembly. I'm generally okay with it. It's worth noting that I build gunpla for fun, so it makes sense to have me be the one to do it. Though, I can't really say that I enjoy building the furniture. The frequent use of Allen keys certainly isn't helping the furniture's case.
This is a really good resource on Game Boy modding and repair..
For my own Color I went with the Hispeedido/OneChip OLED kit. I'm happy with it. I recommend using NiMH rechargeable batteries with it. I get around 5 to 6 hours on two Eneloop Pro AA batteries.
Obligatory picture of the Boy.

As for the Pocket, you're probably going to have to cannibalize the part from another unit. I did a quick search on eBay and did see a few working LCDs for around $50 each. That isn't really a good price since it's possible to find a functional Pocket for around the same price. Though, it can be difficult to find one without screen cancer these days.
If you do check out LBP, do know that all of them were delisted and the official servers shut down a couple years ago. Physical copies are plentiful, but the games had tons of DLC. A lot of it was just cosmetic, but there were a few level packs that added new mechanics. Fortunately, it's not too difficult to find archives and there are custom servers too.
The servers had actually been down for maintenance for months before the shut down was made official. From what I heard it was because someone figured out how to upload malware through custom levels.
Have you played Klonoa? How about LittleBigPlanet?
Also, Wikipedia has a list of 2.5D games if you're looking for something new to play.
I did some quick research and SDDM can do what you want by editing the sddm.conf file. You just have to add the username to HideUsers in the [Users] section.
Depending on which display manager you use you could always just use a theme that requires typing a username rather than selecting from a list. I know there are a few SDDM themes like that.
Is that a Nebelung?
Does Neopets count? I think I made my first account there in either late 2002 or early 2003.
Airport security pre-9/11 was pretty horrendous. Hijackings were surprisingly common compared to today, but the difference was that it was usually for a ransom and/or demanding that the plane go somewhere else. This led to a general policy of just going along with hijackers and letting the authorities deal with it later. The most famous example of this kind of scenario is D. B. Cooper.
An important thing to remember about Aviation in general is that every lesson is written in blood. This leads me to PSA 1771. In 1987 a disgruntled former airline employee got on plane, shot his boss and the flight crew, then intentionally crashed the plane killing everyone else. This incident was entirely caused by the poor security practices at the time. The perpetrator's employee ID hadn't been taken back when he was fired and because he had those credentials he was able to get on the plane without being searched.
According to the BBC, the one exception is the newer Starlink Wi-Fi router, which the company says is manufactured in Texas.
This is exasperating.
I always end up going back to Arch anyways, so it mostly serves to reaffirm that Arch was the right choice for me in the first place.
I run Arch on my laptop, which is the machine I use most.
My personal desktop runs Cachy at the moment because I felt like trying something new.
The family desktop has Debian for its stability and ease of maintenance (I only have to update it like once a month).
I installed Zorin on my mom's ex's computer (and set it to auto update) because he's a bit technologically impaired.
Edit: I use DietPi on my Raspberry Pi 3B. It was the easiest way to get Nextcloud running.