I got divorced about three years ago now and, much like your friend I was afraid that the system was heavily in favor of the woman. I was pushed into making contact with child support by a couple of friends and found that the system is a fair one now, they even told me I was paying too much child support. I went from paying $800 per week (which was what the ex demanded) to $350 per week (income assessed), during covid my income dropped and I'm currently paying $160 per week for 3 children under 15 years of age. All other costs are 50/50 and extracurricular activities have to be agreed to beforehand.
Unfortunately, she wouldn't compromise in conciliation and I had to go through the court to get orders. So now I have access to my children 4 days a fortnight, 2 days during the week and a weekend as well as half the school holidays.
As mentioned above they only calculate costs on taxable income, they don't include cash in bank, super, the business or property only the taxable income they generate.
Also if your friend has full custody then his ex would have to pay him child support, so it would be in his benefit to get into the system as fast as he can.

As for your punting question, I no longer want a relationship and am very happy living the single life and enjoying my time with my kids. When I feel the urge I punt then I walk out the brothel door a free man to do whatever I want whenever I want.