The cost of the best, high end, professional-grade equipment with those kinds of adjustments already made available would seem trivial compared to the cost of having a competent engineer hack the microcontrollers in a consumer product.
The software in cameras is usually working hard not just on the imaging algorithms, but also on correcting for issues, errors, omissions in the basic camera design, and sometimes dubious features. Not likely that manufacturers would want all that stuff hanging out in the wind for public viewing, or that they would dare to intervene trivially in such programmatic houses of cards.
If you are almost happy with jpegs, consider using something like Picasa for RAW conversion. Last time I looked at it, you could waltz through large numbers of RAW conversions to slightly-better-than-jpeg quality in very little time indeed (like several per minute), much faster than with any of the higher end packages.