Don't worry about the problems, if you're willing to address them then yes, I don't see a reason why you can't go somewhere with this. I'm not trying to cut you down, but someone has to ask the hard questions.
I'm not sure liquids on items can be repurposed for the kind of solid material coating you're thinking of, but if you think you can pull it off, all the more power to you! Something similar has been proposed in the past incidentally, regarding
armor. I don't know if it actually got added though. If it did, you might be able to extend that to weapons.
I'm not proposing just different weapons here, I'm proposing introducing a new type that allows for weapons of different lengths without the need to change to another type. Things like a claymore or gladius would fall under long swords and short swords respectively. If the silverised blade forces you to switch training halfway through, people just aren't going to use it, or focus on long swords then use it when it gets longer. Which means the early stages will get neglected, which I don't think you'd want.