Most of the steps of documentation are same. Only PCC and medical are couple of documents which you need to procure post ITA. Rest of the documents are already there with you if you have the nomination.
Not necessarily, nomination required docs for just last 10 years but with ITA they require for all work experience. And proof of funds, requires info of all accounts (including debt) with opening date etc. A 6 month statement of a single account worked for nomination.