I havent really even considered it, because it wouldn't be "fair" to add it when some ppl have alot of coins allready.
I have some somewhat similar ideas tho...
Suppose nothing is impossible when holding the source, but it could possibly require step-by-step implementation and it could possibly reflect into future blocks only.
I think security is more important. What if the attacker attack again. You can make the interest very small in the first month like .1% second month .2% and so on. Once the price go up and down I'm sure pwc will change hands many times.