Would adding clonazepam to methadone and oxycontin help my pain control?

Methadone and oxycon. Firstly both Methadone and Oxycontin are long acting - i would ask why are you taking two long acting medications together. Secondly the use of benzodiazepines such as cloeazepam are not recommended with Methadone - there have been reported deaths from this combination.
No. As above, i generally use only one long acting opioid. I almost never add a benzo to an opioid, especially methadone, as risk of death significantly increases.
No. Taking a drug like Clonazepam with opiates can put you at risk for respiratory depression.
No. Clonazepam is a sedating drug, not a pain killer. Adding Clonazepam to the medications you are taking can increase the risk of death or severe injury.