Well, a good start would be to display the project resolution/fps in the respective render configuration dialogs where the render resolution/fps is configured – so that I don’t have to hunt down what those are from the original video material (I can’t access the project settings while in those dialogs which makes things a little more annoying there.)
Even better would a button there to “take resolution and fps from project settings”.
Yet even better, but a lot more involved, would be to have templates that don’t specify a bitrate, but a quality level (as ffmpeg does at least for h264 encodings) as that could remain constant accross resolutions. With this, you could even offer a “resolution/fps-independent template” to just select on rendering and go without editing anything.
So there you have it, my suggestion for making this a bit better. 🙂