I'm subscribed to this thread, so I saw the full dxdiag before it was trimmed down.
This bit below would suggest you do have a dedicated graphics card the Nvidia GeForce GTX 745. I did some searching on Google and it looks like that card is just a hair slower than the minimum recommended GTX 560, your card is newer though.
You could try reducing the resolution in Windows. Instead of the widescreen 1920x1080 you could pick 1366x768 or a 4:3 resolution 1436x1080. Your graphics card will have less pixels to draw that way. The game won't look as sharp doing that, but the frames per second should be higher.
Otherwise, buying atleast a new GPU is in order. Or waiting for release and hoping the game is more optimized, and more quality setting adjusters in the graphics options.
"-------------
Display Devices
---------------
Card name: NVIDIA GeForce GTX 745
Manufacturer: NVIDIA
Chip type: GeForce GTX 745
DAC type: Integrated RAMDAC
Device Type: Full Device
Device Key: Enum\PCI\VEN_10DE&DEV_1382&SUBSYS_6893103C&REV_A2
Display Memory: 8104 MB
Dedicated Memory: 4035 MB
Shared Memory: 4068 MB
Current Mode: 1842 x 1036 (32 bit) (60Hz)
Monitor Name: Generic PnP Monitor
Monitor Model: ORION
Monitor Id: ORN1209
Native Mode: 1920 x 1080(i) (60.053Hz)
Output Type: HDMI
Driver Name: nvd3dumx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvwgf2umx.dll,nvd3dum,nvwgf2um,nvwgf2um,nvwgf2um
Driver File Version: 10.18.0013.5887 (English)
Driver Version: 10.18.13.5887
DDI Version: 12
Feature Levels: 11.0,10.1,10.0,9.3,9.2,9.1
Driver Model: WDDM 2.0
Graphics Preemption: DMA
Compute Preemption: DMA
Miracast: Not Supported by Graphics driver
Hybrid Graphics GPU: Not Supported
Power P-states: Not Supported
Driver Attributes: Final Retail
Driver Date/Size: 11/2/2015 12:00:00 AM, 15839200 bytes
WHQL Logo'd: Yes
WHQL Date Stamp:
Device Identifier: {D7B71E3E-50C2-11CF-7365-9E481FC2C735}
Vendor ID: 0x10D"