How do I create a custom filter?

I'm sure it's been posted before, but the search feature doesn't let me limit to the EB forums so I get a ton of results. I'm assuming it's just some sort of naming convention.

 

You can do so by going to the Tools tab and clicking on Item Filter editor.

 

that's it? when I do that, it seems to just modify the "Default Filter.json" file, rather than creating a separate one, which means if I have to do a reinstall from scratch, I can't add my changes on in a supplementary fashion. I'd have to overwrite the whole file and hope nothing important had changed in it.

 

I'd like a quick assist with the item filter rules. I'd like to identify and sell every rare I pick up (farming alts). I've created a filter in the vendor section of the item filter area, but it only vendors the chromatics. Yes, I've saved the filter. I also clicked "identify" on the item filter. Is this something I need to take off? (ie no check mark in the box). 250 points for anyone who helps me out.
EB