Mr. P,
Don't worry, I know your not.
It used to be that you had to own an HDB (assuming you got your flat new direct from the HDB) for a minimum of 10 year before you could sell it (and upgrade to a new flat and take advantage of the 2nd/last housing grant (in it's myriad forms - too much for here). A few years back it was reduced to 5 years before you could sell it without being penalized.
As far as the racial quotas are concerned, they still apply. So anywhere you want to go, whether you will be allowed to go there or not depends on the quotas, The same thing goes for trying to sell your existing flat. You cannot just sell it to anybody. Although at times you can. Look in the newpapers for HDB sales. Quite often you will see ads with "Indian Elgible" or open to all races. Depending of the existing quota's in the estate/block where your flat is. With the HDB is doesn't matter how much money you have, if your skin is the wrong colour or your are of the wrong religion, you might not be able to buy that flat you want. Or you might not be able to sell your flat because nobody of the right race has made a offer. Sometimes it sucks! It generally only affects the minorities as you can well imagine. We were lucky when I bought mine on the resale market as my wife is a 7%'r and I'm a 2%'r. I guess we were in the right place at the right time. As I bought the flat from the original Chinese owner.
Generally the upgrade between 5 & 10 years. They buy their first flat as soon as they get married (usually they are 35 or so already!) and have a kid. They will buy a 3 or 4 room flat initially, and depending on family growth, income growth whatever, they will opt for a 5 room or maisonette or now, possibly a low end
condo what with the two starting to merge quality wise. I think we'll see something different during/after this economic mess has settled. I reckon HDB prices, will dropping slightly, won't drop all that much. What we are seeing though is a shakeout of the Condo Market. A lot of upgraders will go directly from their first flats to low end
condos I've got a feeling. This will probably depress the larger 5 room and maisonette prices (like mine) unless there are those people who like larger flats and developed infrastructures (town centre and related knock-on facilities). Something the newer towns don't have yet.
I guess only time will tell now, as we are all in uncharted territory.....