Complete Divestment of Playmate Holdings; Rethinking my approach

I have divested my shares in Playmates Holdings (HKEX: 635). Over the months since Jan, I am slightly worried about a few points of this company:
a) Lower occupancy of investment property. It is noted that the company seems to have an attraction to Savills, having it being the property manager and the property surveyor. AFAIK, their method of valuation is level 3, which is worrying because the increase in value of its properties looks like a bubble in itself.

b) Reducing earning ability of its main toy business. I am not enamored of the quality of its upcoming toys as well. 

c) Slight increase in non-current loans for no reason despite its reasonably high cash position. I note that interest coverage this half is still a safe 20 times or so-- but why incur unnecessary debt?

d) Share buy backs using company's fund is encouraging but I rather the directors buy it using their own pocket and try to improve business.

e) I noted that the investment portfolio has increased by 40-50m or so, but there is no explanation for how they pick stocks, or who is managing their investments. Active investing is not easy-- especially with large money.

Overall gain in investment for Playmates, inclusive of the recent special dividends, is only 10%. This means I sold at break even price.

Moving on, I would like to share some opinions on retail investing.

Walter Schloss is my idol and I still find investing in his way the easiest. His returns might not be the highest, but investing is not about topping the class-- it is about getting decent returns over long period of time. I do think that if you end up in the top 25% of the investing community every year over long period of time (10 years), the results would be lovely. 

However, buying a small position over many companies requires a full time job. After reading The Dhandho Investor, I feel the practical method is to buy when you have ascertain a huge opportunity, and bet heavily. I think 8 is enough for diversification. 

In addition, the age-old belief in value investing is that you either buy a so-so company at a cheap price, or a great company at a fair price. Over time, I do think that the latter approach is easier. It is definitely easier to spot a company when it is cheap. If I have a sizable (400k-1m) amount of money to work with, leaving 50% of it for cheap companies is plausible. With the amount of money I have, I do need to rethink my approach to compound it efficiently.