I use DT both via the GUI or via the command line darktable-cli. Hundreds of frames rather than thousands though.
I've found DT a bit unstable for sure but am running PPA unstable and git builds. You could try using OpenCL in DT if you're vid card is up to it, that may help.
Regarding floating point EXR's I think they're half float at best, via DT 16bit rather than 32bit full float not that it really matters much about having 32bit, massive files and little to benefit storing images that way for the most of us.
Imagemagick will also give you EXR output, you'll need to compile a hdri version possibly unless things have changed with IM.
Another option might be to use dcraw to go dng to 16bit tif, you'll have control over debayer algo, WB, sensor saturation level, color space but going to tif will bake WB but Blenders tools are totally lacking for raw anyway.
**EDIT**
Here's a simple script I just hacked for the CLI to create 16bit EXR's from the .dng's:
for file in *.dng ; do
dcraw -c -w -H 1 -o 5 -q 3 -4 $file | convert - -depth 16 "./EXR/$(basename "$file" .dng).exr"
done
If you put Raw2dng.exe in a folder along with your dng's, create a sub folder called 'EXR', save the above shell script above in there too, give it execute permissions, make sure you have dcraw and a hdri build of imagemagick installed, then fire up a terminal, cd to folder and start the shell script. You should get 16bit exr's in the EXR folder. :-) Of coarse you can use tif or png for 16bit too but blender will read the exr's as half float or float whatever.
If you import the exr's via the Movie Clip editor change the color space input to XYZ.
If you don't want XYZ color space the dcraw settings and explanation is here:
http://www.guillermoluijk.com/tutorial/dcraw/index_en.htmSo you could change the dcraw settings to suit. I just did:
-c send to standard out
-w auto white balance
-h '1' linear mode no clipped highlights
-o '5' XYZ color space (0=none (no colour management), 1=sRGB, 2=AdobeRGB, 3=WideGamut, 4=ProPhoto, 5=XYZ)
-q '3' Best quality Bayer demosaicing (0=bilinear, 1=VNG, 2=PPG, 3=AHD)
-4 Creates linear 16bit rather than 8bit gamma
If raw2dng would pipe to standard out we could avoid creating the dng's at all. Obviously a lot more could be added to the script like mkdir for each named RAW and sending the .dngs or EXR's to those named folders etc but meh...
