1) Yes, IMM 5490 is the correct form
2) She's applying to New Delhi. Vergeville is inside Canada only. However, you will mail the enter application to CPC-M first as directed in the guide.
3) No, the doctor will give her a sheet to include with her application. He also submits results to CIC. CIC will make sure the pictures match to ensure the medical was given by the right person (fraud deterent - sad, but true!).
Here is the Outland Guide:
Make sure your wife has signed all her forms before she send them to you. A complete application includes your forms and her forms