Understanding forex trading costs - IC Markets

I’m reading through the product document for IC Markets. They provide what looks to be a comprehensive example of calculating your Forex costs when you buy/sell your position.

I’m trying to understand a few things

  1. Financing Charge/Finance Credit - “Where lots = 1 (100,000 = 1 lot)” - shouldn’t this be 5 lots given in the example 5 lots were purchased and sold?
  2. Point size = $1 (since the 5th decimal place = 1 point on AUD/USD and this is
    equal to USD1.00) - where does this 1 come from?
  3. Where does the bid-ask spread come into your final calculation?