A: Use VLC's J and K keys during playback, or remux with MKVToolNix setting a positive or negative delay.
If you absolutely must have an offline, DRM-free file for archival or educational purposes (e.g., a school project on dyslexia), consider purchasing the official disc (available on Amazon.in and Rarewaves). You can then legally rip it for personal use using MakeMKV.
A: Unofficial rips often strip secondary subtitle tracks. Download a full .srt from OpenSubtitles that includes song translations.