Will my ability to play games be significantly affected compared to Windows?
It depends on how often you play games with aggressive anti cheat, or games on non-steam platforms. Games like Valorant and Fortnite probably won’t work at all. But I do a ton of non-competative multiplayer (and single player) gaming that is not inhibited at all.
Heroic launcher is your best bet for non-steam platforms (GoG, Epic, Amazon), and lutris/bottles should probably be your 3rd option (I’ve used both for battle.net). But steam games running through proton should “just work”.
Can I mod games as freely and as easily as I do on Windows?
The actual modding should be arguably more accessible. You technically have control over the entire kernel, so nothing is going to stop you from doing whatever you want. The only problem you may run into is if you’re dependent on modding tools that were only made for windows. Some of those tools are basically spyware anyway (ex. Curse), and often times the open source community has made its own alternative you should be using instead.
If a program has no Linux version, is it unusable, or are there workarounds?
YMMV. Valve has done a lot of heavy lifting to get proton to be a one-stop-shop for running windows games on Linux but you can add a program as a non-steam game, launch it through steam, and it often just works.
Wine is your other option. Sometimes the community has gotten windows apps running reliably in wine or proton, other times no one has ever tried it or it’s too much of a headache to get working. protondb.com has user reports for how various games run.
Can Linux run programs that rely on frameworks like .NET or other Windows-specific libraries?
The short version is yes. The long version is the same as the previous answer.
How do OS updates work in Linux? Is there a “Linux Update” program like what Windows has?
Most distros come with some form of package manager that works similarly to an app store on your phone (an app store is basically a package manager with purchases). Ideally, everything you want to run can be installed through the distro’s package manager, and then you use the package manager to update everything. But sometimes the software doesn’t exist in the package manager, and you have to download, run, update, and sometimes even build from source, your own programs. Those programs usually have a guide on the best way to run it on popular distros.
How does digital security work on Linux? Is it more vulnerable due to being open source? Is there integrated antivirus software, or will I have to source that myself?
It is actually more secure due to being open source. Source code can be audited by anyone rather than relying on “security by obscurity”. There are antivirus programs, but I don’t know much about them. Generally, don’t run programs from shady sources, don’t expose your machine to the open internet, and don’t run everything as root and you should be fine.
Are GPU drivers reliable on Linux?
Yes, though historically AMD has better support for the newer features asked for by Linux compositors (namely Wayland). Nvidia’s drivers are still not fully open source, but otherwise work fine. Driver bugs are rare in my experience.
Can Linux (in the case of a misconfiguration or serious failure) potentially damage hardware?
To the same extent that windows can, yes. But if your concern is YOU misconfiguring something to cause Linux to do that, you shouldn’t have to worry about it. It is unlikely you will be interfacing directly with the kernel at all. Most distros configure the kernel in some specific way they want and you never worry about it. And still, a proper kernel-level driver should ensure that it will never send commands that could damage something, even if the config vars are incorrect.
And also, what distro might be best for me?
First off, install Ventoy to a USB drive. Then take advantage of Linux’s ability to “live boot” by downloading several .iso’s for several different distros onto the USB. Then boot off the USB, and you should be presented with a handy menu of ISOs to pick from. This will make trying out a bunch of different options really easy, without actually installing anything to your hard drive.
I’d say try grabbing mint, fedora, Pop!Os, and opensuse to start. Maybe also try Zorin. These are all geared toward new Linux users.
Re: modding
Nothing is consistent with modding. The idea of a game having “modding support” is a relatively recent concept. For most of gaming history, “modding” meant hacking the game (or sometimes hardware) to do what they want in spite of the creator’s intentions, rather than in accordance with them.
All that said, if you can get a vanilla windows binary running on Linux, getting mods working is usually the same process that it is on windows, especially if the mod is just swapping out files. The same files exist somewhere in your Linux filesystem and can be tampered with just like they can on windows.
If the mod involves running a 3rd party tool to edit a process’ memory in real time, that could be more involved since the windows version of the tool might be making some assumptions that are not necessarily valid when running in a Linux wine/proton environment. In order to get it working, you may need technical knowledge of how the mod is doing what it’s doing.