This also completely ignores the concept of pruning old transactions, which can be done if need be.
Is there a consensus that pruning is actually possible and doable?
Yes. Transactions which have had all outputs spent and have had ? transactions past them are no longer needed to be stored.
Speaking about the competition (a lot) gives it importance.
If that is the attitude darkcoin wants to have, we might as well give up now. In general, pretending competition doesn't exist results in one thing, and one thing only. Absolute failure.
That's not the attitude of Darkcoin, that's my opinion. And when I say "speaking" read "criticizing" don't twist it.