One of those Linux posts...

I would stick to something mainstream, so that it will be easier to get help if needed. Most people choices these days, at least as much as I can see are - Linux Mint, Arch Linux and it's derivatives (for example EndeavourOS, CachyOS), Fedora and it's derivatives (for example Nobara) and OpenSUSE.

Dual-booting on the same drive shouldn't be a big issue, just don't do Windows Updates without waiting like a week before doing it, so that you can see if there are reports of the update ruining the Linux's EFI files.

Just make a new partition with your free space and install the Linux distro on that partition. Or you can make another partition yourself for the Linux's EFI files (something like 1GB of size), that should help avoid the issues that might arise from Windows Updates.

I've been using Linux Mint for 8 months now as my main operating system (dual boot, but never had to boot into windows - just didn't need to). My impressions of the OS are excellent. So far it's the best and most trouble-free Linux distribution I've ever tried (before I switched to Linux I tried different distributions from time to time). I have tried: Ubuntu (almost all variations), MX Linux, Debian, Pop!_OS, Manjaro, Fedora. On each of these distributions sooner or later some problems popped up. Mint, on the other hand, does not give me any trouble and works like clockwork. I am so used to and love this OS that I can't even look at Windows anymore. 99% of the games I've run have worked without any problems.
Dual boot works without problems if it is on the same disk. You don't need any guides, just start with a bootable flash drive, choose a disk and how much free space to take, and then the installer will do everything by itself.

As for Garuda Linux. I haven't tried it myself, but I watched a review by a linux blogger, and his conclusion (like mine) was that it's just a piece of garbage.
PikaOS - first time I've heard of it. But it doesn't even have a page or rating on Distrowatch. Also, since November 14, they stopped publishing source code on GitHub, which also does not inspire confidence.
In general, I wouldn't recommend digging into any obscure unpopular distributions. They are in their place for a reason. As a rule, there are no hidden gems.

Gaming on Linux is largely dealt with by the native Steam client and Steam's Proton. Just make sure your distro has a current Steam package.

Since you have experience, I think Arch would be the best choice for you, but there's support for gaming on any distro. Arch's Steam requires multilib, and you should get the proper Vulkan driver mainly for Proton emulation.

I've been using Linux as my personal daily driver for 20+ years, and gaming for about the last 10. Currently using Pop!_OS (desktop) and Gentoo (laptop).
I'm far from an expert, because for at lest the last 5+ years, Linux just works (for me), and I don't spend much time fiddling with it. Yes it has it's quirks (usually hardware related), but I'm sure Windows does too.

Regarding choice of distro. It's a bit of a minefield! Personally I would recommend starting with something mainstream, mature and with a large community (Mint, Ubuntu, Pop!_OS), before looking at one of the many specialised distros (there are several gaming oriented distros). You can even install SteamOS.

Considering PikaOS, it looks nice, but I'm not sure it's stable enough. It started as a copy of Nobara, but replaced the Fedora base with Ubuntu, and then again switching to Debian unstable (sid) base. I imagine upgrading due to these changes would be difficult and require a full re-install. The community is small: they have no forums, Reddit is dead, and only offer support on Discord.

I suggest getting a large USB stick, and installing Ventoy to it. You then just copy any Linux distro's Live DVD iso file over to it (i.e. without installing directly to USB) allowing you to choose which distro to try at boot time. This lets you quickly get a feel for many different distros, and how they behave with your hardware, without having to install anything to hard disk.

Before installing, if you've anything you do not want to lose make a back up. The simplest way, if you have space on another disk is to just image the disk (using something like Clonezilla which you just add to your Ventoy USB).

I recommend WSL2 for programming and just stick to Windows. Dual boot never works out for me. I end up just staying in Windows.

Last time I tried linux, I spent like 4 hours trying to get my mouse's extra buttons to work and then gave up. If you like spending your days editing config files instead of actually getting anything done, give linux a try.

Any modern, popular and competent distro, as I've heard of Mint, should offer you to make/use a partition somewhere and detect and configure all other OSes installed for multi-booting. i can't say for sure with Mint, but I bet it does it well.

The first time I tried Linux was with Ubuntu and it did all that perfectly, and it was more than 15 years ago.

If you don't see that happening while trying to install, then abort and go to some Mint forums and ask about it. Or maybe you'd like to do it before trying.

Damn, now I want to try Mint too...