What problems exist with the alt coin Namecoin and what can be done to fix them?
First, NMC is not worthless, it have a value and is traded on bitparking ( https://exchange.bitparking.com/main )  and btc-e ( https://btc-e.com/exchange ), with decent daily trading volume; people saying nmc is worthless are just people wanting to attract you to other altchains( most of them being scams imo ) .

Second, namecoin is an opensource network, it cant really die as long as people use it.
 Also, namecoin is the oldest and most serious alternative coin ( altchain ) to bitcoin.
 NMC price have gone down with merged mining ( increased supply ), but merged mining also made namecoin very secure and long lasting.
 As long as someone will maintain the software ( https://github.com/namecoin/namecoin ) namecoin will rock as the oldest and best altchain.

Real issues are :


possibility to store small files in the blockchain, could lead to increased blockchain size ( see https://bitcointalk.org/index.php?topic=145278.0 and https://github.com/runn1ng/namecoin-files )
small community, not enough tools, websites, graphical client . . . )