2005 stock Crossfire with identical troubles, speedometer sits at 0, Brake + ESP + BAS lights all illuminated and spoiler permanently deployed. I have spent 3 weeks reading everything online. I have had no time to get to attempting a proper look at the issues but I have pulled two codes (P0281 and P0291)

Based on the feedback from those who have managed to resolve issues of identical nature I am planning to:
A) Replace battery
B) Replace Speed sensors
C) Relay control module
D) Light my car on fire

Thoughts ?
Anyone have some solid advice for actually resolving this ?