I think that your 1. point is the biggest reason why most alt coins fail.  There were unfortunately some coins that got only developed to scam people. Looking at them is not really helpful because the designed from the start to only be active for a few months after launch. As soon as the developers manage to get rid of their coins, trading should slowly disappear until the coin is worthless. For active managed coins that try and succeed, its very important to set enough money away for the time after the launch. A successful coin not only needs promotion before the launch phase but also after it. The most important aspect is to have liquidity in the coin to allow quickly buying and selling. The less trading happens in a coin the more will be investors cautious to invest in it.