> 1. If your circuit ever sees a stalled motor, then there will be a
>  contest of sorts.  Who will give out first?  The power supply ?
> The fets ? The wiring ?

The only universal stall detector I could think of is a motion
sensor. If there's PWM and the motor ain't going nowhere.....

Because this could be used with any number of motors, I'm not
sure if a current or voltage sensor is going to work without any
tinkering for the individual motor

> 2. You are being quite conservative in your gate drive setup.
> For example, your bottom fets have their excitation clamped
> at 7.5 volts.  Is this enough to guarantee good turn on at all
> loads and temperatures?

http://www.irf.com/product-info/datasheets/data/irl3402.pdf

According to the datasheet, output is virtually the same for
comparable Vds voltage at 25C and 150C (Vds = 2.25V - 7V).
Vds = 5V seems to be a good compromise between output
and the 7V maximum

> 3. Finally, dynamic effects

That's probably where the fun will start

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