omitting 'what'

Question

I know that you can omit what in the following sentence.

There's more to it than what meets the eye.

Can I omit what in the following sentences? If not, what is the reason?

1. I had done three times more than (what) was needed
2. There's more to the bacon shortage than (what) has been reported
3. You've got more than (what) you thought.
4. What unites us is greater than (what) divides us.
5. It seems that we focus more on the impossibilities than (what) can be done.

Answer 1

When you have a comparative, what can be omitted:

more ... than needed
more ... than was needed
more ... than what was needed

When the comparands are nominals, what cannot be omitted:

what unites us ... what divides us

the impossibilities ... what can be done

Here is another example where there are nominal comparands:

My car is faster than what you drive.

my car ... what you drive