This is what I can gather about "fewer versus less" and "myriad" from my Garner's Modern English Usage.

Fewer emphasizes number; less emphasizes quantity. So, I would ask myself if I prefer saying the number of bugs or the quantity of bugs, and then choose accordingly. I prefer number, here. On account of that, I prefer fewer.

As to myriad, though it can be used as a noun (and apparently its use as a noun predates its use as an adjective), written language for the past 150-plus years prefers the adjective. (When Garner is talking about written language, he's talking about quality writing.)

I'm not saying you're wrong. But, style is as much about a sense of style as anything. Keeping language from going to the dogs requires a bit of dressing up.