That is a good reaction to Godot's growing popularity.
I recommend using GDScript instead of messing with C#, which is supported but much more difficult to set up. GDScript is really similar to Python, the editor has Intellisense/autocomplete (even for strings!) and all the documentation is built in under the Help menu. It's a very very pleasant experience overall. It's also the first time I've been able to work fully offline thanks to the extensive built in help, and this does wonders for productivity.
Unity feels like Windows, they stack on top of each other all the latest shiny features to attract customers resulting in a massive mess instead of thinking about a coherent overall architecture/UI. Their latest ECS system is an eg of this, they have just stacked on top of the pile a more FP approach although their architecture is not necessarily designed for that, but hey, FP and data-driven is trendy so let's add this too on the pile .
The real drawback right now with Godot is the 3D renderer which is okay but clearly not on par with UE or Unity, but 4.0 is coming with a re-written from scratch new Vulkan renderer.
Unity's licensing terms are complicated and litigious, and because of this their tooling is locked to their online platform -- you can't use Unity without logging in. This means they at any time they can lock you out of their tools. I'm honestly more comfortable with older licensing models where you'd get your software on a disc for a fee. Not only do you not own the engine, you don't own what you created on it. They can lock you not only out of selling, but out of even compiling or editing your own game.
I get that the games industry is driven by revenue, and I'm comfortable with buying and selling games as a product. I'm even comfortable with selling commercial software at a flat fee. But that doesn't mean we can't collaborate on engines and tooling outside of a revenue context to move the state of the art forward. Most advances in game development have been locked for decades in the proprietary engines of large studios, and every serious indie developer had to develop in 2d or start from scratch. Unity's more open licensing model was a huge step in the right direction and has inspired a lot of creativity but it's still fundamentally a closed platform that can lock further innovations behind a paywall and deprive creators of tools.
This is their right -- they're not hiding the terms of their licensing at all. But if as an indie developer you really want to own your game's code instead of locking it into Unity's platform, Godot is the way to go.
You definitely can, but it requires working with a sales rep to buy named or floating licenses that are served up by a locally run license server. I would be surprised if they did this for single quantity license purchases, though.
Additionally, after subscribing for two years, you can stop subscribing at any time and continue to use the latest version of the editor at the time your subscription expires, perpetually, as in "perpetual license that you own." This was announced at the same time they announced the switch from perpetual licensing to subscription licenses, if I remember correctly.
With regards to the perpetual license, this is rooted in a promise from the company that they will continue to license it "perpetually", not that it is impossible for them to shut down your software. What happens if their licensing servers go down, or they decide that you as a user are so egregiously in breach of their contract that they cannot continue their perpetual license? This can be due to arbitrary restrictions, such as a local government passing laws which do not allow them to continue their license. Consider if an old version of the Unity engine is in violation of GDPR, for example. They would not be legally able to continue perpetual licensing for their product, and they would be forced to shut you down. That is not ownership, and do not let anyone fool you into thinking it is.