I did think about that. I had a nice little "read me" that I was going to send everyone that outlined various processes of the app. One of them was how to import.Why not send the users a properly formatted template? If you allow them to simply do their own thing, you will never have a reliable process since they will simply keep making different errors.
It was a goal of mine to eventually get it all to work in the backend so that way I more or less knew the data coming in was only what needed to be brought in. One because if the code did it, there were less chance of errors from them missing something accidentally. Which may say me time in having to trap various errors.