(re: Programming in Sierra games) Both issues stem from the same thing, the speed of modern computers. The SoundBlaster driver problem arises from when the driver first polls the hardware, a modern machine responds so fast that it is as if the driver received no reply at all, hence the “Unable to initialize your audio hardware” error message (This is easily fixed by the GOSIERRA patch or one of the updated drivers from Sierra’s FTP.) The timing problems come from using the CPU’s clock as a timer function in their code. This causes the infamous errors such as those in QfG 4.
As far as LucasArts games go, There are many problems there as well. For those games we are fortunate to have ScummVM, which solves many of those issues (though not all.) It is too bad that FreeSCI is not as far in development as ScummVM is, though this is understandable as SCI is A LOT more complicated and versatile than Scumm is.