I followed almost the same strategy as yours. When I have to decide whether to invest, no matter for equities or real estate, I set the following rules to follow
1) profitability: no matter calculated from cap rate, ROI, or irr, it has to be above 7%
2) liquidity: liquid ratio has to be at least 105% for every single assets, and 145% overall for my whole business. Working capital ratio has to be 200%+
3) solvency: it has to be at least 100%, gearing at 30% to avoid the risk of unexpected rate change