Full disclosure: I was involved in composite toolmaking in aerospace for quite a few years and worked on the B2 bomber producing the (stupid) rotating refueling receptacle, was involved in the C-17 wing to body fairing program and duct work, worked in a company that produced composite engine nacelles and various other composite parts, worked for a company that produced parts for Boeing, etc.
I think the term 'forged carbon fiber' is a VERY poor descriptor; what's actually being done, as some one mentioned above, is making parts with both an inner and outer mold line, obviating the necessity for vacuum bagging with bleed cloth or release film. An acquaintance of mine was producing motorcycle muffler shrouds in carbon and used such a process. The prepreg was laid up on an aluminum mandrel then an outer steel mold with a slight taper was placed over the layup and it was bagged. When autoclaved to 350°F the aluminum expanded much more than the steel, compressing the layup and producing a very nice surface finish. It was pretty slick and saved a load of time and material. I think the 'forging' process is similar.
As far as resin ratios, prepreg is manufactured to an optimum ratio; excess resin just adds weight and reduces strength. When the layup is bagged, an absorbent layer is incorporated to capture any excess bleed resin during the cure as well as provide a path for air to be removed by the vacuum ports; don't forget that the autoclave is pressurized to more than 100 psi with nitrogen. There isn't much resin coming out, however. Resins are designed for different temperature cures, from fairly low temperatures to very high, depending on what use the part is designed for. The layup orients carbon direction for carry loads; for example, unidirectional tape has fibers parallel to each other and can be used to direct loads. Many weaves are available and ply orientation is very critical for strength. A layup might have ply orientations of ±90°, 45°, etc, depending on what is required of the part. Layups can be many layers and incorporate nomex honeycomb or other materials for stiffness. An adhesive layer without fibers can be used as the first ply to provide a clean, smooth finish.
Forged carbon fiber? I'd like to see a press or forging hammer work cured carbon material.......