A datasheet has record selectors as you probably noticed, and there's a reason for that. It's so that you don't have to go to a lot of effort to be able to select the entire row and press Delete to delete the record. To want to disable or remove the selector and still select the entire row for deletion makes no sense. You could do something with a continuous form view, but as you noted, changing column widths isn't possible. I see no way to do what you want, which as I said, makes no sense based on the information you provided. If you're simply trying to make your form look like some other application, then I'm afraid you're out of luck.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.