"What are one of..."
Should read "What is (the main) problem..." for an answer in the singular or "What are the main problems..." for a multiple.
Better still, recast the whole question.
Re. Chipmunk turning. In days of old it was an accepted technique to give a burst of power with a little forward stick to lift the tail to make a tight turn possible. It is a tad hard on the tailpost, though, and thus rarely seen these days (when you are paying for your own maintenance). Some types require a little help to get the tailwheel out of the steering range to caster fully for a tight turn though this is usually accomplished with a touch of one brake.
I've never worried about nosing over on landing a taildragger; there are other things to think about at that time. Rough or waterlogged ground is more likely to cause concern.
I reckon the most relevant consideration is directional control.