Bellala

I have read many articles and the documents from DIBP. There are some points that I need to clarify and confirm. Please give us some answers if anyone professional or experienced before. 1. Do I need skill assessment? 2. Could I apply 186 direct scheme for PR without applying 457 first for 2 years and than 186? In terms of company, is there any difference for them to prepare the documents and payment for 457 and 186? 3. For how long should the company advertise the recruitment for the marketing vacancies? is that hard to prove ? 4. How much roughly the company need to pay? Thanks for the answers.