Rosy,
We plan to improve work with text in O&A editor. I understand your request. Currently I didn't find universal solution for text typing, because a text object in PTE can be shows 3D rotated that may complicates the text editing.
Text fonts in the interface of PTE are scalable according setting in Windows Control panel. In other words font size is the same as in other apps. Personally I set 125% and 150% in Windows for all apps, including PTE, on my PCs.