A surgical correction [CTR] is possible fix for airway obstruction necess. Trach, how soon do you rec doing this major surgery with high risk of complications?

When it's safe. Your question is a little confusing. Not sure what ctr is. Anytime the benefits outweigh the risks, that's the time to do the intervention, whether it be surgery or medications. The airway is the most important of all body functions. Without a patent airway, nothing else works. If there is an obstructed airway, then the sooner a procedure to correct this is done, then the better.
It depends. Ctr means crico-tracheal resection. It means removing the upper part of the windpipe just under the voicebox, and putting the two ends back together. It can be done for children or adults with severe narrowing of the airway. It can be done anytime after 3-4 weeks after a tracheotomy.
See below. I'd recommend discussing this with your child's pediatrician, pediatric pulmonologist, and the surgeon. They can work with you to decide when, and whether, this surgery should be planned, and discuss risks of the procedure. Without knowing your child's entire medical history and current clinical status, it's difficult to give a definitive answer; they know your child better.