If the elevator linkage is broken, the trim should work as normal.
If the elevator is jammed whole so it can't move, the trim works the opposite way to normal.
Very worrying to read about Whirly's experience. It would likely be fatal on departure (I think we have all seen that video of the big twin turboprop doing it) but once airborne one should be able to steer with just the rudder. Using the rudder is fairly standard for lazy pilots (like me) flying long distances and doing small corrections.
It's also handy if you have the notorious Honeywell KFC225 autopilot and your 6th (no kidding) roll servo has just gone up in smoke, so vertical control still works but, whenever the AP is engaged, the ailerons are dead and jammed solid. So, you fly along, with the flight director on, and doing small heading adjustments with the rudder....