Compare your sheet with this using (say) 60/300

http://members.aol.com/johnp71/confint.html

It says your observed strike rate of 20% could be "really as bad" as 15.62%.

Therefore you'd want a ROT of 20/15.62 = 28% POT to compensate.

28% is far bigger than your reduction of 10%.

Also just bet A+B+C+D+E with your disposable income on AusTote with its introductory 2% rake.

The worst thing that can happen is you going crazy after some beginner's luck.

It is more character-building if you lose a bit as that should force you to research harder to lift your game.