It really depends HOW crossed it is. How old is he? If you can post a pic, we can give better feedback. Sometimes it can be trimmed; other times, it's just too crossed...I had one that I used to take to an avian vet every 6 weeks for a major trim. She did okay until she was about 8 months, and then passed due to not being able to get enough feed, but I know there are others who have them that they do just fine. You need to provide deep dishes for their feed, because they sort of shovel it in with the bottom beat, so to speak.
I doubt it. I tried saving a few and they all starved to death eventually. Knowing what i do know, I would cull sooner, as soon as they look like they are not able to eat enough to have a quality life.
I tried every thing to save a cross beaked splash BLRW. One morning I found her dead and I was embarrassed by just how thin she actually was. I should have culled her from the start. As Wynette stated they bill their food and require a deep dish in order to feed. Even with that they waste more feed than they eat. Sorry that I couldn't offer some only known by old men super fix but there just isn't one. The best course of action is to put her down.
I had a little cross beaked roo that I was able to mix oatmeal in with his feed and he did well until one day the other baby roo figured out they he couldn't defend himself and it ended in a bloody battle. To try to prevent him from suffering too long I crushed up advil(alot of them) and added it to yogurt and fed it to him...I thought this would finish him off quickly and end his pain and suffering but by the next morning he was doing much better...throughout that second day he got worse and I gave him a warm bath to clean him up...after the bath I kept him wrapped in a warm towel and he drifted off the sleep never to wake again. It was the saddest thing! I was determined to let him live out his life as long as he was not suffering and eating well. We are not "farmy" kinda people or one of us would have been brave enough to cull him at any given point thus the advil overdose. It was a horrible loss and my little son just loved "Special"(chicken's name) sooo much...he & his Daddy buried Special in our woods. It was a sad day...hopefully we will not have to go through that again. Just wanted to share so if your chick survives(and happens to be a roo) you'll be more cautious and protective of him than I was. Blessings, Keri