Yes.
As far as efficiency, you fell on your face. Sorry man. The 35% for the car is the engine. That's the max possible, real IC engines in consumer cars are closer to 25%. Your novel idea that that is higher than electric cars get is funny, but no. Also, battery charging using the battery technologies already used in cars is closer to 85% in the worst case, and over 90% average. Nobody is building cars with lead acid. And "battery discharge" is not 75%, the average is over 90%. 75% is the lowest efficiency, which you get briefly at the end of the cycle when the battery is already charged and you're only using a tiny bit of current to top it off. The main part of the charge that uses most of the power is at the higher end of the efficiency range for the battery. You're whacking battery efficiency down twice with made-up numbers and pretending to be science-y.
Battery charging efficiency is actually near 100% below 70% charge. Remember, you're not doing much work here, physically. There is no reason to desire there to be an extra loss here. ;) Discharge loss is also normally only a few percent, not 25%. Almost all the losses in your "equation" are from made-up numbers that are nowhere close to reality.
Fuel cell storage efficiency is only 20-60%. No surprise, because hydrogen atoms are larger than electrons, and so filling up the cell requires vastly more physical work.
Flywheels are super-heavy. The funny part about what you say there is that small flywheels used the same way as electric regenerative braking can increase fuel efficiency in a city, with frequent start/stop, but the mass of flywheel you'd need to be useful at a 50+ mile range would be really heavy, and have huge friction losses. It can be done, it has been done, but you get a slow tank that is inefficient, not a fuel-saver.
Not having better numbers is no excuse for just making them up as if a guess what you use when you can't be bothered to look any of it up, and don't already know about the technologies.