Would it be possible to revisit the 100% concentration requirement of using a sanowret crystal? Not asking to reduce the concentration costs at all, just the requirement of starting at 100% rather then just having enough in your pool to pay the cost.

Thieves are the only guild that uses concentration as a resource and when running khri hunting etc are rarely at 100% concentration. Thus it can be difficult to get the most out of your khri while weaving in sanowret crystal uses, no other guild really runs into this issue.

Thanks for your consideration.

Sorry about that, I stand corrected. It unevenly effects traders and thieves and like you pointed out, probably the guilds who need to use it the most.

You need to be a magic user to use Rhinestones. NMUs can use items like the wands and such recently available at Duskruin, but I believe they get no arcana experience for doing so.