1. No.
2. No
3. No
Some IR visas allow for “derivatives” eg spouse, minor children, to be included on the application. IR 5 does not.
Each of your parents application are stand alone. Now that they are both at the NVC, you can call as the petitioner of both, and request that they be “linked”. Hopefully this will have them processing and sent to the Consulate together. If this doesn’t happen, then the next opportunity is when the first one gets to the consulate… email and request that the first one be held until the second one arrives and that interview happen together