The Pig is very very good at: carry lots of bombs, a long way, at very low altitudes, at high speed, in bad weather, at night. It is a very good BOMBER.
The pig is not very good at dog-fighting, it has poor cockpit visibilty, a large radar cross section, poor air-air radar capability. It is a very bad fighter.
The amount of money required to convert into a decent fighter would be more than than the cost of buying an F-22. Not cost effective.
As for your point 6 - I can reliably tell you that the complete opposite is true. The vast majority of RAAF pilots who what to fly 'Fast Jets' have the F/A-18 as their first choice. To suggest otherwise is unbelievably naive.