In that case I think we'd need skill books up to high levels for everything.
Tailoring books only go up to like 3, but there's crafting up to like 8. During normal rust-enabled play, you'd never be able to craft these things, you'd have to very purposefully metagame it and spend a few days crafting tank tops to get your skill high enough for chitinous armor.
With a vastly expanded range like that I think we'd want to have a quality modifier in there as well, so you'd be able to make a lot of stuff at a fairly low level, but it'd take a lot more time to make really good versions of things, perhaps with lower weight and encumberance and higher effectiveness (be that armor or warmth or environmental protection.) Actually crafting would have it relatively easy, as it's inherently time-intensive.
Like I said, I'm skeptical of people signing off on the 10,000 hour plan o anything similar, since it mandates literally hours and hours of grinding, since that's how it works in real life... Even though you can work around it to a great deal by having a "practice for x hours" command.
... guns... 10,000 hours of firing practice... just how many rounds would that be? 0_0
And yes, I think the way forward with rust GlyphGryph outlined is the right way to proceed, but in addition to that I think overal skill leveling speed will need to come down a bit.
Also I think rust will have exponential backoff balanced against a rate determined by skill level, so 1 lvl of rust might happen as soon as overnight at high levels, but the 2nd level would take a week, etc...