I can believe the bit about needing new wings for existing airframes. There are quite a few A10 fuselages in the DM AFB boneyard missing their wings after they were pulled to use as replacements.
As far as friendly fire is concerned, that is a situation that has happened ever since the invention of ranged weapons and will happen again as long as people continue to engage in warfare. To sit in judgement from the safety of your home keyboard is rather hypocritical, particularly if you have never even served anywhere.
There is a ton of difference in using a hovering platform at 25' altitude vs one that is moving about 400 MPH in a much more vulnerable altitude in the arena with modern radar guided guns as well as missiles. It's not a video game with instant zoom and "god's eye" cameras available to look over the battlefield. Nothing in either system can instantly define what is a red target vs a blue target and placement of troops / equipment in a fluid environment is never predictable all the time. Even the vaunted IFF can falter. Those folks do the best job they can and have an enviable record in regards to friendly fire, more so than ever before. People and machines are fallible.
There simply is no other airframe in the AF inventory that can do the same job of close ground support as the A10. Many of the blue suiters have zoomie fixation and forget that there is more to the conflict than simply airspace control and fast but limited ordinance delivery. Combat takes time and if you can't loiter while the situation develops, you reduce the impact you have on the battle field.