Snapping. It's ridiculous in C4D. A lot easier in apps like Maya or even blender. Along with snapping would be align. Quadcaps, relaxing points while maintaining shape, using normals or other shapes for extrusions, and so much more. Repeat last tool. Hell.. getting out of a tool requires either switching to the Move tool or the Select tool, in order to drop my current tool.
Modeling modality: I shouldn't have to press M to get into modeling mode. It should already be present when I automatically shift into point, edge or poly mode. While some hotkeys for functions like Extrude exist outside of having to press M first. However, if I press D (extrude) in Model mode, it doesn't change me over a modeling mode to use it. It just sits there with an extrude mouse icon, looking at me all stupid like. Make hotkey sets where they will shift based mode or function? For instance, in model mode with the viewport active, CTRL-R invokes the Render View. However, if in modeling mode, CTRL-R invokes the Add Edge Loops tool. Speaking of edge loops, if I lay down an edge loop, my scroll wheel BEGS to be used. Let it dial in more loops, ffs!!! I shouldn't have to move my mouse at all, especially to change the number of cuts in the Attributes Panel, or the cute UI at the top with the +/-. Make C4D more efficient. The UI looks great, and back in the day it was considered artist friendly. These days artists want tools that expedite their content creation, including utilizing scroll wheels and hot keys and hotkey sets.