Prepping sheetrock after removing chair rails

We are renovating a house that had chair rails along the walls and we pulled them off. I was told that we'll have to float sheet work where the chair rails were, otherwise the line where the paint stopped would always be visible. I was also tolf that after floating the new sheetrock, the entire room would have to be re-textured so it would look uniform.



It looks like the texture was applied under the chair rails, so if I can avoid having to float new sheetrock, I shouldn't have to apply texture.



Is there anything that can bail me out of all the work and expense, or is floating sheetrock and putting on new texture the only option?

Prepping sheetrock after removing chair rails