Learning: "How to store items"

[Black_knights55]

Will the use of many clientr.tag create some kind of lag or is it ok to use lots of them?
And if I use this example:
clientr.item.(@itemname) = {type, quantity};

How do I change only the quantity? I'm not sure how that way works at all.

And, can I just create a weapon, lets say a "mining bag" and then just create some this.iron_ore=quantity, this.silver_ore, etc? And if it's possible, I would be able to find those variables with findweapon("mining bag").iron_ore or something like that, right?