There's no reason to keep the host key as right control if it causes problems like that. You can set it to something different in VirtualBox's global preferences (Control-G) > Input > Virtual Machine.
Also, you may prefer to run your VMs headless with vboxheadless (man vboxheadless). May save you some time and frustration, and video memory. Then ssh into them by going into the guest settings and forwarding port 22 to a host port (I use 12322).
There's no reason to keep the host key as right control if it causes problems like that. You can set it to something different in VirtualBox's global preferences (Control-G) > Input > Virtual Machine.
Also, you may prefer to run your VMs headless with vboxheadless (man vboxheadless). May save you some time and frustration, and video memory. Then ssh into them by going into the guest settings and forwarding port 22 to a host port (I use 12322).