Perhaps the most consistently irritating lack in Axure is the limited styling that you can apply to text fields (ie input for forms).
Given that the tendency these days is almost universally towards the use of flat design, I always switch off the border which has a default 3D effect. However, I do want the (white) field to display a flat border (usually grey), and to be able to change the thickness and colour of the border, for example to indicate the field has focus, or that it is in error, or that it has been corrected, etc.
I already raised a support call about this some time ago, and basically the only way to achieve styling effects on fields is to use JS, or else to put a box round the field, and play with that. The first is complicated while the second has its limitations and is incredibly tedious when there are a lot of fields.