r/Nyingma

I understand Outer Tantras (Kriya, Charya, Yoga) emphasize external ritual, while Inner Tantras (Mahayoga, Anuyoga, Atiyoga) emphasize visualization.

1. Beyond that, what are the major differences in view, conduct, meditation, and resultant attainment?

2. Are yidams like Tara and Chenrezig practiced across all six, or are certain deities specific to particular tantra classes?

3. Can one receive empowerments for all six levels and attain Buddhahood within a single lifetime?

4. Outer Tantras specify progressively fewer lifetimes—Kriya the most, Charya fewer, Yoga fewest—to reach Buddhahood. Inner Tantras (Mahayoga, Anuyoga, Atiyoga) attain Buddhahood in one lifetime. Given that, what is the difference in the resulting buddhahood among these three Inner Tantras themselves?

How are there iconography different ?

How is there practice different ?

And is there some hierarchy?

And both are essentially Tara herself?

Is there any Vajrapani Prayer which can be chanted by everyone as part of there daily practice?