Couple both 33 in finance

Cash 300k
Cpf 150k
HDB worth 500k o/s loan of 90k
Car worth 80k

Annual income of 260k combined. Save approx 100kpa

1) should we keep the HDB and buy a second property now or sell it and buy 2 private property to avoid the ABSD?
2) amidst this bullish stock market, should we still put our cash into investment?