The problem with these sorts of thread on "Fixing" crossbows, is that they are trying to improve a weapon that is the way it is for good reasons. Unless you are trying to get more characters to use crossbows for flavor reasons, basically a crossbow IS inferior in essentially every aspect to a bow. That is why it is inferior to a bow in the game. Complaining that they are not as good as a bow is like complaining that short swords are not as effective as a 2-handed-sword and trying to "fix them".
A bow is an expert's weapon, the crossbow is essentially an amature's weapon. D&D characters especially figher characters who are specializing in a missile weapon are by definition experts.
To give a more recent example, Unix/Linux vs windows. For real wireheads, there's nothing like U/L. You can essentially build, customize and control your operating system and enviroment to a T. They can make the programs sing, dance and automate most of their work for them and it's essentially bullet proof from system problems. The downside is that U/L is horribly complex and unfriendly to those who lack a considerable amount of experience and who don't understand the logic behind the system and software.
Windows on the other hand, is simple enough that you can train anyone with half a brain to use it and accomplish say 50% of what the expert on U/L can with regards to daily computing tasks and it won't involve 3-5 years of experience. The "Joe" user with windows can't do nearly as much or nearly as quickly as the expert does, but they cost 1/10th as much and you can crank them out by the dozen.
Given a choice the a bunch of U/L experts are clearly superior to the "Joe" windows users, but they
1) Take a long time to train.
2) Cost a lot more to keep
3) Hurt more when you loose one.
Just replace U/L with Archers/Bow and "Joe" Windows with Crosbowman and it's essentially the same situation.
Bows have a vastly higher rate of fire, because in the hands of an expert they DO have a vastly higher rate of fire. They are martial rather than simple weapons, because a bow takes a significant amount of training and expertise to use properly. All you need with a crossbow is to be able to point the thing and pull the trigger, something simple enough that even a mage can do it. A number of missile feats are usless with a crossbow for good practical reasons, even if you don't like "reality" intruding on your game.
Basically, there is no need to "fix" crossbows any more than there is a "need" to "fix" fighters not using magic and wizards not using swords.