For your question, Input signal recording dry and with dynamics at the same time, yes this is possible with a special trick.
In Totalmix you have to do special routing.
The input channel with your signal stays clean without dynamics.
This channel is for recording the dry signal. Enable it for DuRec.
Then you have to route it to an output channel other than directly below.
Let's make an example :
Your input signal comes in on input channel 9/10.
Route it to output channel 7/8
Use dynamics on this outputchannel.
Activate Loopback inside this channel (click wrenchtool button).
Now your signal with compression is forwarded onto input channel 7/8.
Enable Input channel 7/8 for DuRec, this is the signal with compression.
Both stereo-channels will be recorded. One dry and one with compression.
M1-Sequoia, Madiface Pro, Digiface USB, Babyface silver and blue