yes, i agree with you on both counts.
it is certainly possible to achieve 20% p.a. over a 10 year period, or even double your capital every 3-4 years. i have no doubt that the stocks listed on sgx can give good returns when bought at a good price, unless you manage a 9 digit portfolio which will reduce your selection.
if i only use valuation ratios to pick my stocks, my entire portfolio will consist of s-chips (and not even the good ones)! thankfully, i don't. definitely, we must do our due diligence. i think 80% of my portfolio is producing dividend, but at the end of the day, i'm still looking for capital appreciation (if not, how to double capital in 3-4 years, right?). one other criteria that is important to me is the sustainability of the company's business model. if they are deemed able to survive/thrive (not limp along) for the next 5 years, coupled with manageable debt and attractive valuations (big discount), i will buy them. i don't pay too much attention to richly valued stocks, at least not until they become cheap enough for me to decide to do some research.
of course, if you have time, you could research all the stocks listed and value them accordingly. so you won't have to split hairs on what to buy when the market crashes.