Go here:
http://www.sonido-7.com/d8b/files/userg ... Bv5_OM.pdfDownload the manual and you should get a good idea of what the console is capable and incapable of doing.
To answer your first question...no, the D8B is not primarily a DAW controller out of the box. It is capable of controlling DAWs via MIDI, complimented with the 8 channel limited V5 HUI controller layer. But it not a "Mackie Controller" type of thing. It requires setup on both the D8B and DAW ends to get reasonable communication happening.
Limitations? Depends on what your needs are. Technically, the 48kHz S/R of the unit could be a limitation if you require to work at 88.2kHz or higher. 12 Mic pre's could be a limitation if you need to handle more than 12 mics at a time and the D8B is all you have to work with. No pre-master fader inserts could be an issue. Hard to say not knowing what kind of work you need to do and what kind of gear you already have.