Thats impossible unless you make all classes equally good at everything. The balance depends mainly on the type of campaign the DM is running.
Please walk me down this slippery slope...
lets focus on non combat 1st (only because combat is the only thing you seem to think anyone cares about)
what if all rogues had a list of 4-10 things they could do like **Fast talk** make a check to make someone do something as long as it isn't against there base nature or **hide in plain sight**
then the fighter got 4-10 things they could do like **Gibs' slap** remove a condtion but deal 1d4 damage to an ally or **Intimadating smile**
then the wizard and cleric still had there spells
then you could even say something like Defualt fighters start with 2 combat abilities and 0 social ones... and rogues start with 1 and 1... but if you are willing to take the time you can mix and match...
then go with 4e 1/2 level to attack but give fighters a combat ability to get +1 and weapon spec as an apotion...
then we can all have things to do and all play the characters we want...
in my homebrew everyone starts 1st level with Con score HP... then gets a HD every other level d12 for fighters d10 for other combat classes, d8 for rogue cleric and monk types and d6 for wizards... at odd levels you only get +1/+2/+3 hp