1) In terms of byproduct mining only around 27% of silver comes from primary silver mining with the rest being byproduct mining. But if you look at the chart only around 15% comes as a byproduct of gold. You can see around 41% comes as a byproduct of Copper and Lead/Zinc and silver is far more valuable then those metals so I doubt they would be throwing the silver away in those cases. Also even the gold mines would process the silver unless its an an extremely low grade/ore of silver in the mix that is non-viable to extract. I am sure there are a few examples here and there of what you are saying but I am hesitant to believe its common until I see evidence otherwise.
2) Yes industrial demand is currently close to 50% according to the table I posted in my previous post. A lot of silver bulls think that industrial demand and investment demand will both increase concurrently over time. Like you I am also not convinced by the bull case for silver but that being said the bull case is not completely without merit. The bull case is based on a combination of increased penetration of electronic devices globally (e.g. smart phones, etc) as well as increased uses of green technology (solar panels, etc), as well as an increase in investment demand for physical bullion if the general public ever loses faith in fiat.
3) Yes green energy is a scam but it that does not mean it can't keep growing for a long time. Who knows how long it will take for people to wise up to the scam. Central Banking is a complete scam and that has been going strong for well over 100 years with the majority of the populace none the wiser to the fleecing they are perpetually on the receiving end of.
I do not think dealers are getting rich from 1 ounce coins (unless its a big company that is minting its own rounds).
They have to buy them at a hefty premium from the mints and often only add $3 - $5 per coin markup (for the most popular and liquid coins. It can be more for other coins) onto the price as it is a competitive market with many bullion dealers who compete mostly on price. The fact that often if you buy a few thousand 1 ounce American silver eagles, Canadian Maples, etc in one go at best you might get $1 - $2 per coin off the single coin price. That kind of tells that what I am saying is likely to be right.
There are occasional periods where markups increase due to a shortage of retail silver products but that is because the mint puts up the price of those coins when there is shortage (it takes mints a while to catch up to a sudden spike in demand and mint more coins) and the dealers pass on that cost increase to customers.
