So this is what you would like to happen:
Low speed stability
At low speed, a nose down demand is introduced in reference to IAS, instead of angle of attack, and alternate law changes to direct law.
It is available, whatever the slats/flaps configuration, and it is active from about 5 kt up to about 10 kt above the stall warning speed, depending on the aircraft's weight and slats/flaps configuration.
A gentle progressive nose down signal is introduced, which tends to keep the speed from falling below these values. The pilot can override this demand.
Bank angle compensation is provided.
In addition, aural stall alert (“STALL, STALL” synthetic voice then cricket) is triggered at an appropriate margin from the stall condition.
The PFD speed scale is modified to show a black/red barber pole below the stall warning.
Vα prot and Vα max are replaced by Vsw (stall warning speed).
The α floor protection is inoperative.
High speed stability
Above VMO/MMO, a nose up demand is introduced to avoid an excessive increase in speed.
The pilot can override this demand.
The high speed protection symbol (VMO + 4) disappears.
In addition, the overspeed warning (VMO + 4 or MMO + 0.006) remains available.
Pitch attitude protection
Lost.
If I read you correctly you are advocating that with a faulty sensor input leading to the aircraft believing it is going too slowly, you would like it to revert to Direct Law. IMHO that is a not a very good idea. Far better to have angle of attack protections in Normal Law.
Perhaps you have tried your theories out in the sim?