Finding total energy for RC discharged capacitor at t = ∞?
Apply a sanity check, the cap is in series with a resistor R1, so Req clearly cannot be less then the 3k series resistance....

I would start by rolling R4,5,6 up into one resistor, and then combining R2,3 into a single resistor, just to simplify the thing (Resistors in series and parallel). 

Then for B (and maybe it is just me) I would convert the 1V voltage source in series with a resistor to a current source in parallel with a resistor, which at T0+ ends up in parallel with R2.... Combine with R2 and convert back to voltage source in series with resistor, at which point you have 1 loop of three series connected components (plus voltage source), should be soluble from there I would have thought? 

Hint, once you have that little series network, solve for current then calculate the relevant voltage.