I guess I'm not really 100% clear on what you're asking here?
Generally speaking, besides maybe Gentoo's approach, Arch with the AUR probably has the widest selection of packages (more accurately pkgbuilds) in a single location, although AUR packages are not binaries and must be built from source. Adding in the Chaotic AUR, you probably now have the widest selection of pre-built binaries as well. On top of this Arch does support adding external repositories, and Arch-based distros that don't come with the AUR enabled still support doing so. You may want to have a read of this Archwiki page if you'd like to get a better understanding of package management, both on Arch and in general.
This may be the closest you can come to that, but I've never used it. Honestly, I don't see the need - Arch offers more software than literally anyone could ever need, and even if I find a package that's not in another Arch repo or the AUR, I can just build it from source anyway. Not to mention that trying to make assorted distro stuff play nice together just sounds like a headache, however good the tools are.
Again, not sure what you mean here, maybe I'm just missing something? To launch another OS from within a booted OS, you have to use virtualization of some kind as far as I'm aware. Fancy passthrough options are possible to make VMs run more natively, but this is not something I've looked into.
Well, Android-x86 is touchy and odd regardless, and at least last time I checked it wasn't really recommended to run it on bare metal. I wouldn't necessarily consider x86 "original Android" either - even if one considers mainline Android to be a "Linux distro" (which, kind of) it's an ARM-native platform. Your best solution here is probably going to still be a virtual machine, or depending on what you actually want to test something like Anbox or Waydroid could be better.
Just run Garuda More seriously, it's probably better to just find one distro that works for you. If what you need is the widest selection of software, Arch is probably the way you want to go, unless you are prepared to install Gentoo. Neither are really recommended for "noobs" as you say, but taking the time to actually install Arch yourself will teach you a LOT about Linux. You will hit snags, hiccups, etc along this process, and if you need a working machine every day you should probably give it a couple shots in a VM. I've never run across any software I needed that I couldn't either build from the AUR or from source directly.
Virtualization is an extremely powerful and useful tool once you get a little more familiarity with it, and you can certainly back up configs from one if you wish to apply them to another of the same OS. It's even possible to allow VM's to access a shared folder on your hard drive, and with the right hardware and a little work they can even use some components of your machine directly.
Unfortunately not. It's not a matter of drivers at that point. Mobile devices are usually ARM chipsets, desktops are usually not. Things built for one architecture will not run on another. In the case of Android specifically, running packages (.apk's in this case) is achievable via Anbox and related tools like I mentioned above, but otherwise mostly no.
Last But Not Least
I respect your curiosity. Linux and the world of free and open source software is a wonderful place to be, and a perpetual learning experience. There are a lot of resources available for you if you want to know more, just be prepared for some reading. This guide if very good if you need help looking for something in particular, and I can't recommend it enough.
Garuda linux is a small community, and while it offers a very easy install process and a lot of useful tools, it is still Arch which means it's going to involve much of the same experiences. Forums like this one, and generally for Arch-derivatives in general, are not always friendly to noobs, especially if you come off as not having done your own research. I hope you don't let this discourage you. As long as you're thoughtful, ask good questions, and do your own work ahead of time, you'll find many who are happy to help!
I, for one, am always happy to show people around. If you have more questions on this topic (and the mods decide this thread is cool // in the right place) feel free to ask. If you're curious about other stuff, you're also welcome to shoot me a direct message here.
EDIT: guess I may have been a little off base with a couple things here as per Naman's reply. Hope this is helpful anyway!
I guess what you are trying to achieve is possible. You are trying to achieve some extent of sandboxing libraries. We actually implement it in our build server to build packages, without interfering with host OS ( We use Arch there, but other Linux distros should be possible as well, not sure of android though ). I have no idea, to be honest on how to do that, because I was not the one who wrote the code.
Dont know if this is what you are asking for but you could try bedrock linux, I tested it and it worked "fine" on gnome but crappy on deepin due to kwin method of requesting time but that should be fixed on a recent kwin like arch's. I dont know if android x86 is supported on bedrock linux but you could try.
I was just going to suggest Bedrock haha. Nice. I also used it briefly in the past, it was quite the adventure! However, things didn't work as well as I liked (looking at desktop environments and Systemd services). Still, the concept is pretty phenomenal
Systemd-nspawn is used here to isolate things. Think of it as chroot on steroids. Using the nspawn.org prebuilt images, its actually damn easy to run different Distros with Systemd as PID 1 (read: be able to run services just in a regular OS). You can even run nested nspawn containers iirc.
I used it to get in contact with the gentoo world and it was quite cool but mesa oomed my laptop during compilation so I uninstalled it, my next experiment was with deepin linux+arch apps but due to kwin bug it eat all my cpu. I would have tried to use a garuda + something but btrfs+grub is not supported and anyways garuda with chaotic aur does not need anything else xD
Systemd-nspawn is used here to isolate things. Think of it as chroot on steroids.
That's the best solution I can think of, if running a vm is OoO. I did that years ago with Gentoo. What a coincidence xD It was a ton of fiddling around and Android was kinda nicer (smaller and slimmer) back in the days ngl ^^.
But you can do a ton with those containers.
@virat_17 I like your curiosity keep it. Out of the box needs lead to out of the box tools.
I hope it will work for you in that case.
Should I learn Directly linux from scratch stuffs or something like gentoo linux
I'm ready put some time on it and learn some things
Arch installation went wrong
Once I installed arch Linux on VM but stuck at chroot, I made some research but no success to chroot my arch on VM and downloading stuffs again and again quite annoying so I decided to install from gui like installation on real machine. I also read arch offline installation wiki. Finally I come to know that damn shell scripts make my life easier.
Finally stick with Garuda Linux
After arch installtion that I found Manjaro and Garuda based on Arch and the this is the story of mine
I liked Garuda more than Manjaro so I installed it on real hardware
But I still Install distroes on Virtual Machine
My first script
Arch installation thought me more things,
I was sick of some proprietary chemical drawing software, so I think to make some intractive script rather than just installing a software so that I could use it LaTeX and Libre office, My first shell script for drawing chemicals here anyone who want to draw chemical structure may use it
For drawing chemicals I used Jchempaint a lightweight drawing software and used to genarate smiles or *.smi files [a Java application]