Con is the second most important stat of every class.
With crafting everthing becomes more easier. Wizards are generally weak early game, unless you abuse scroll making, then they are powerfull all the time.
I think ranged combat is primarly pretty weak. But sometimes that's all your character can do because he is stuck or something, but otherwise, yes melee is way more powerfull. Also early game where slayer arrows still work, it's good to use them.
Having said that, you will need your clerics to keep your wizard alive.
Generally wizard need at least one guardian assigned to protect the wizard. Mid game , stone skin can make anything super resilient, even the wizard.