Believe this at your own risk I'd say.

For a start, this argument is completely disproved by market observations. I don't know why anybody even tries to promote it anymore. If you really think that investors are buying network security rather than token scarcity then the most cheaply secured mined blockchains would rise to the top of the rankings. But they don't, the ones with the biggest hashrates do - not because they expend the most energy but because they're demonstrably the most scarce.

Scarcity is not a numerical concept (i.e. you can't create scarcity simply by issuing a small number of anything), it's a reflection of the amount of effort required to acquire the thing. In blockchains, the cost of that effort puts an initial price on the next block. It is not a "speculative" value, it's real, based on the level of prevailing competition in effect at the point of mining the block.

That is not a measure of competitiveness. By that measure you could demonstrate that a coin ranked at 200 position is "more competitive" than Bitcoin or Ethereum. The point to address is Dash's valuation against competing mined assets that do not have split reward ratios.

There's a very simple reason we're less competitive than them: we have to collect far more fiat from markets than they do, proportionally for each block mined. We need to collect the mining cost PLUS whatever proportion of the masternode reward is sold. As the masternode network gets larger, that overhead gets larger. Our competitors only have to collect the mining cost.