Hi, I'll try to answer your questions with the little knowledge I have
- So how come this occupation has changed from Open to Limited on the ACT list when only 3 invites have been issued and 3480 positions are left.
You should check the dates of the report and compare them with the dates of the last update on the state's list, they are probably more up to date than the skillselect report, It could also be due that some states have less positions available than others and that they have a backlog of applications to solve
- if I apply for my skills assessment and after my result at that time if this skill is being shown as closed in all the states then what happens.
You should check for how long is your assessment valid, it usually is for the next two years after the result date, if the skill is shown as closed you will have to wait for the next year to applySorry I can't be of anymore help but I'm not sure if the quotas are resetted every year