File a Tax return in Australia and if it shows your pension as already taxed or tax exempt, the Thai authorities will be okay with it. If a pension isn't exempted from tax at home, you will be taxed the amount you transfer into Thailand of course.
You may check through Immigration past midnight to get an extra day, but here comes some even better idea: Stay in arrival area for another 24 hours and you will have even 2 more days in Thailand.