Bounds? = Object Bounds -> You got that in AD/AP as well
TexSpace? = Texture Space = What rules are used to place 2D textures on some 3D object.
PassIndex 0? = Pass refers to the render for a layer that might be used reflections, one for basic color, one for shadows etc. -> Index is just a number that indicates to the software which pass or material you are referring about.
DupliVerts? = Some verts that define the location where clones of an object should be placed. Dupli = Duplicates
Where are my drawing tools? -> Those would be in the paint mode + in case of the grease pencil animation addon in the left viewport panel where the grease pencil tool is located.
Now I can agree that Blender UI is not the best out there, but it’s not the worst either. C4D & MODO UI’s are definitely more beginner friendly but once you gain more experience one will see they have serious issues of their own as well.
As far as the naming conventions? Well...they might seem Blender weird ones or engineer level. But once you move from 2D to 3D a lot of possibilities open and not just for animations. As such the amount of terms & software tools increase significantly. This also affects the UI after all, because you have to fit all that stuff somewhere. I am not defending or talking about Blender in particular. All software that seriously deal with 3D besides some 2D animations have some names for tools/functions that are common to other software and some of their own which can be difficult to remember. That’s just the industry. Had the same issue as you when I switched from AI to a 3D software, lot’s of new stuff, many overwhelming. Want to learn AI/PS or AD/AP. You can pretty much learn all of it in 1-2 days if you’re serious about it. Want to learn the tools in a 3D software? Have fun, the amount of them is like 40-70x times more then what you have in AD+AP. This only covers knowing where tools are and what options they have, not for what to use them for. Often at pro level you need to master more then just 1 software. :D
You can definetely do 2D animations in a 3D software. And do amazing things that are simply not possible in a standard 2D app. However expect some significant or steep learning curve for getting proficient regardless of your 3D app you want to learn. No pain, no gain ;)