Can a child develop tic side effects from Adderall (dextroamphetamine and racemic amphetamine) 1 year after stopping the medication?

Likely not. One year is a very long time. This is probably a red herring.
No. Tics can sometimes occur as a side effect of stimulant medication, but only when the medication is being used. If the Adderall (dextroamphetamine and racemic amphetamine) was stopped a year ago the current tics are not related to past medication use.
It depends. Age is a big factor. Tics commonly emerge between the ages of 8-10. So, if a child is on a stimulant such as Adderall (dextroamphetamine and racemic amphetamine) at age 6 or 7, tics might emerge a year or so later. Evidence suggests that stimulants don't cause tics but they can unmask them or worsen them in people who are vulnerable to having tics.
No. Tics can sometimes occur as a side effect of stimulant medication, but only when the medication is being used. If the Adderall (dextroamphetamine and racemic amphetamine) was stopped a year ago the current tics are not related to past medication use.
Unlikely. This is much too late for the body to react. Remember that the vast majority of children with tics are on no medications whatsoever when they begin the problem.