Thanks for the feedback! I'm a Vim user myself; it's still unclear to me why they kept making text editors after that one. ;-)
RStudio does very little in the way of Vim key handling; the Vim mode you see is a feature of the editing component we use, ACE. We pick up new versions of the editor regularly, but it's been a while since our last one, so we don't have all the Vim mode goodness that the latest version does. You can play with the ACE Kitchen Sink to see some new Vim editor features that will eventually migrate to RStudio (switch "Key Binding" to "Vim"): http://ace.c9.io/build/kitchen-sink.html
That said, most of the commands you mentioned aren't likely to make it into RStudio soon, since ACE hasn't picked them up yet.
If you want to live in no-compromise Vim, some folks from the R community have created an RStudio-like environment using Vim and tmux. More here: http://manuals.bioinformatics.ucr.edu/home/programming-in-r/vim-r