I have two questions:

Can i use Interdimensional Matter Transporter to save one of my monsters from Raigeki?

And

Does Divine Wrath work on monsters like Manju of the Ten Thousand hands?

1. Yes. IMT will remove your monster before Raigeki can destroy it.

2. Yes, Manju's effect is triggered upon his successful normal or flip summoning, so you can chain Divine Wrath to the effect to negate it and destroy Manju.