Question

Which type has the most super effectivenesss and most defences?

Answer 1

Ground and fighting are tied for first, hitting Five types super-effectively

As for Defense, it is Steel Types, at an average of 110.8
Also, they lead in Special Defense at the average of 82.9

Sources: Steel Pokemon Page & Type advantage page

Answer 2

Steel is super effective against 2 types and 11 moves are not very effective against it along with one no effect move. Fighting and Ground are super effective against 5 types.
Overall, it would be Fighting types, which is super effective against 5 types and 3 types are not very effective against it.