Yup, problems and solutions discussion is what we do
And in the end it is all up to schema. Just saying, that some of the mentioned problems really are none. Whether a camera moves or not is irrelevant (there is one 4x4 camera matrix and that is it), lighting and textures both are not needed for the camera rendering (think infrared, not photographic), and the system the game uses to draw objects is pretty standard - also lowering the resolution of a frame buffer object you render a scene to means
rendering is done at that resolution (there is no afterwards compression of a much more detailed scene). Think of it this way: when rendering to a display block at 128x128 (which would be very good quality actually) is making the GPU think your screen is 128x128 for one rendering process.
Rendering something onto a 128x128 FBO is in an
ideal engine (means only the GPU is the bottleneck ever) about four times as fast as rendering to a 256x256 FBO, and optimized engines get pretty close. Your average HD screen requires 1920x1080 pixels to be rendered.
If an option to adjust resolution of camera output was given to the player in game options (256x256 being the max like texture sizes, maybe 32x32 the min), the effect on performance for the average player would be guaranteed to be negligible.
On a sidenote, minecraft was actually an abomination in terms of engine performance. Schema did it in a far more planned way from the start. The Schine engine is even in the current state already built with many future features in mind, from the way it works (there seems to be going on a lot of optimization even at this stage, including some advanced mesh simplification, or noone would ever be able to render a 1km titan). Of course, minecraft still has to be credited for spawning the cubeworld scenario, something that has changed much of gaming.