Re: DAI random performance drops
I see you have a laptop.
The dxdiag shows Intel HD graphics as the primary display adapter. EA's games have a bad habit of not switching to the right graphics card, meaning you're likely playing on your processor's weak built-in chip. That would explain the poor performance.
You can force the game to always use the Nvidia GPU. In the Nvidia control panel, go to 'manage 3D settings' and then click the tab 'program settings'. You should then select DAI from the dropdown list and under 'select the preferred graphics processor' you should pick the Nvidia GPU.
Here's what it looks like, except in this example they use tesv.exe (Skyrim) instead of Dragon Age:
