You can feed the output of the DVD recorder to watch Freeview channels. (You'll effectively be using it as a Freeview box anyway). However if you get rid of your Freeview box you won't be able to watch one channel while viewing another. (You'll only have one digital tuner, which will need to feed the same signal to both your TV and the disk).
If you keep the Freeview box you'll be able to use it (just as you do now) to watch digital TV, but you'll also be able to use the DVD Recorder to record a different channel.
Chris