I'm not classifying it as "good" or "bad", as it is not. But it is providing freebies - by RAW, the sorcerer needs a Martial Weapon Proficiency feat. There are feats for some ability to cast 0 level spells as well. I'm looking to fill out how far these bonuses would go in your game.
As a comparable, if we have the world's greatest role player getting the maximum bonuses he could get, how does his character compare to the guy who just rolls dice, collects loot and levels up after several levels, or even role plays very well his continued efforts to advance with the skills and abilities provided by his class, rather than those provided by other classes. If that sorcerer spent the same amount of time working with the wizard on how to extend a spell's staying power, would he get a more traditional sorcerer ability of the Extend Spell feat, just as he is getting the less traditional Martial proficiency with a warhammer?
As a comparable, if we have the world's greatest role player getting the maximum bonuses he could get, how does his character compare to the guy who just rolls dice, collects loot and levels up after several levels, or even role plays very well his continued efforts to advance with the skills and abilities provided by his class, rather than those provided by other classes. If that sorcerer spent the same amount of time working with the wizard on how to extend a spell's staying power, would he get a more traditional sorcerer ability of the Extend Spell feat, just as he is getting the less traditional Martial proficiency with a warhammer?