What to look for on site visits that builders don't show

After 7 years of renting, I'm finally taking the plunge in Ghaziabad. For investors, construction quality kitna matter karti hai? Like, Sarvodaya Om Nilay mein, initial cracks ya seepage future resale value pe kitna affect karte hain? Aur yeh fancy clubhouses, kya woh really tenants attract karte hain ya bas maintenance charge badhate hain? Site visit pe kya red flags dekhein? Hope this helps others.