Well, the Pro 3 was advertised for game play. To everybody, that means high end games and not games like Solitaire or Chess. Looks to me like you already gave it a real good test because the Guild Wars series was very well written.
You may be able to do a 'trade off' by trimming some of the enhanced graphics features in the game setup. Not preferred but more functional and may reduce the load.
Now then, Update 2 is coming around on August 12th and will be posted on Windows Update as "August Update". There maybe some serious fixes included in that upgrade for all models.
Intel has had a serious problem with the 4000HD graphics series for sometime. Most people had an update for Windows 7 and Windows 8 with both i5 and i7 processors where the update would download but fail to install. No matter what you did, it would fail.
Intel just released a stack of fixes about a week ago which was sent out to developers and that update stack for the Intel video should be in that August upgrade to Update 2.
Don't get rid of the machine; there may be some hope for it coming very soon. No details where given regarding Update 2 except a bunch of major fixes for issues but nothing listed. Microsoft is keeping completely quiet on it.
Personally, I think that the throttling of the i5 (and now i7) models is a temporary firmware installed to keep them from overheating. No proof of that but if it is fixed, that restriction may be removed.
Looking forward for "Yosemite" myself. After it is released, a month later, iOS8 comes out as well. Get ready for the new "flat" look!