The Game Idea That I Cannot Build Yet in Unreal Engine

You bite me, so it's possible just need knowledge Cpp…. Yeah it's impossible 😂

I'll preface this by saying I don't have experience with unreal, but I do have a lot with other 3d software and some with C/C++. It seems like the issue isn't related to what you can do in code, but to understanding the math. Gimble lock isn't related to inverting movement, but rather to locking consecutive rotations. For example, if I was applying rotations in XYZ order and I rotated around the Y in a certain way, I could line up my X and Z axes, since my Z axis depends on my Y rotation, thereby locking me out of a degree of freedom. In your case, it'd be looking straight up at the ceiling (not turning 180, but 90), making your roll and yaw be rotations about the same axis (since you're doing the rotation in world space). Like others have suggested it seems like to solve your issue you just want your controller to operate in local space, not world, which I imagine you can do in blueprints! Cool project!

I would very much encourage you to learn some text based coding because it's great. If you're committed to Unreal then C++ is probably the best option (although Nim is also I think quite a nature option now and, in my mind, a nicer easier language, but it doesn't have the same kind of learning resources behind it). If you are going to go full in on learning to code with text based coding there are other engines with easier language to learn that C++ such as Godot's GDScript, Defold's Lua, or even C# with something like Unity (although I have ideological reasons for my skin to crawl mentioning it) Flax or Godot (again). That said, changing engines is obviously a big deal so while I do think it's worth thinking about once you're considering doing more complex text based programming with quaternions that doesn't mean it's necessarily worth actually going ahead and switching, just that now you're considerations have changed is worth looking to see if you're still using the best tool for the job.

Hey gimbal lock occurs when you play with the euler angles rotating the character – you can switch to quaternions to move your player and it should just go away. Use FQuat and Rotator to Quaternion I think – though its been a while since I used Unreal

The best method is to take the FPS template and change the movement to fly… Is it that easy and this problem is fixed? There are also tons of tutorials for flying movement in YouTube, many solutions if you search in UE forums or ask for solutions.The movement itself is your least problem, but I have seen pretty good tutorials for the rest of the ideas.

Hey, I've been making games for 10+ years and I think the idea is good, great even. However, as someone who has made multiple online games I don't think you understand how complicated it is to have the online elements of the idea implemented, they require a lot of backend handling and needs a server solution that a simple .IO game couldn't handle (I think, never made one)
I think also is that the primary appeal of .IO games is that they are simple, easy to pickup and has most of the information is given to the player right away, a full 3D-axis in-space game could make things not so simple which requires delicate map/game design to not make players become lost.
Finally, I'm commenting this because I think you didn't fail, you just naturally realized your limitations. Play around them, if you are starting your journey now, scale down your game to be a 2D-plane controller ship game, offline, with much simpler mechanics so that you have something done, before moving to a higher dimension (literally)
Hope this helps, cheers

Cant you just take the current rotation into account to change the location of the input?

Looks amazing 😊