The EP robot can handle being at peak torques for about ~7 seconds and for a very long time (hours in theory) at 1/3 of peak. Depending on where you are between peak torque and 1/3 of peak will determine how long it will be before the motors overheat and stop (once cooled down they will start again).
There are many ways to manage unstable feelings in certain areas, here are some ideas:
Set up a series of targets in an area and give each one a “mass” and simulate gravity pulling the end point towards a series of different targets simultaneously.
Set up a series of targets to act as one end of a spring, calculate all of the forces each spring exerts on the end point simultaneously
Curl fields can provide a very unstable feeling especially the higher your hand speed
For a pinball sort of effect you could use several targets in an area that impose a perturbation at some angle relative to how the end point touched the target.
For some very strange effect combine some of these idea, ex. the simulated springs with the pinball effect.
Ian also had some ideas that involve sending a random signal into the scaling factor of a constant loads block (with filtering for robot and subject safety!)