Should I eliminate my preamp?

This is a very smart move, unless you need any of the facilities offered by the pre amp, such as a phono input , the option to switch between multiple inputs, or tone control. But for a basic system with just a disc player and perhaps (if your Oppo alllows) an optical input for e.g. a television and/or Chromecast Audio this is fine.
I do effectively the same in my home office system: computer as source, into an ODAC usb DAC, into an Emotiva Control Freak volume control, into a Quad 405- power amplifer. It works like a treat. Adding an extra link in the chain can only degenerate the signal.
Pre amplifiers were unavoidable in the old days, because various sources had pretty divergent output levels, and in particular the turntable, that needed RIAA equalization as well. These days the 2.0 volt cd redbook output standard for rca has been adopted by quite a few other sources like many DACs. As it so happens, that is also a common input sensitivity for many power amplifiers (double this for balanced).

I guess I want the music as it is rather than with added 'life'.

The argument about dynamics is wrong. An electrical signal comes out of the Oppo and goes into the power amp. What would be pre amp do? Change the signal?
As for digital volume control. That argument was true years ago. These days DACs have enough bit depth to avoid this problem. There is a paper by ESS somewhere but I do not have the time now to look for it.