What makes any silver alloy more tarnish resistant is germanium. So I believe any sterling alloy with germanium added will have adequate tarnish resistance. Argentine is nice because it can be heat treated to harden similar to white gold.
You cannot rhodium plate silver without under plating. Usually copper then nickel then rhodium. Plating silver directly with rhodium will ruin your solution. Rhodium solutions very expensive now. As others suggested use other types of sterling. Stuller has one called continuum also.
It depends what you want to use them for. Using it for western style I radius the face slightly and slightly bent. That will make nice curved lines. For Florentine I usually use a bent liner especially on curved surfaces. It's a good idea to swipe the graver along a piece of leather with some...
Try using silver solder instead of 18k, clean very well and flux twice. If you have to use gold solder use one that has a low melting point. Using a bushy flame and patients brushing the flame all over the piece. Also, try soldering it on a charcoal block.
Well it depends on your budget I guess. A few things that come to mind are; a good torch, ring roller, gravers, burs and drills, pliers, optivisor and a sturdy bench and good light. A GRS benchmate is a good investment but not necessary.h
When you start you will know what tools are needed to...
I really don’t know the what the problem is that you’re having. I was having a similar problem a few years back. I had to get cataract surgery and that solved my problem. Maybe ask someone else if they are seeing the same view you are seeing through the scope.