Kosaraju’s Algorithm - why transpose?
Taking the transpose and using the list based on finishing time both together ensure that if you have edge A->B(in original graph) where A and B are simply connected sub-graphs than in second dfs A would have finished before start of B(See that in transposed graph edge is from B->A). If we do not take transpose then this is not ensured.

Example:

1->2

2->3

3->4

4->2

3->5

dfs(decreasing finishing time finishing times):1,2,3,5,4
Now if you start from 4 you will visit 5 through 4->2->3->5. But 4 and 5 are not simply connected.

For the second part you may or may not get reversed arrays depending on the order of supplying vertices.