Reading through your proposed actions I would combine 1 and 3.

I think multiple feedbacks might be much but out of all the auctions I would only leave one. I would make it NEGATIVE. I had a similar situation happen with decks of cards where I bought 4 dozen decks and paid almost $20 for shiipping which ended up costing about 8 or 9. The seller did discount but I felt that it was a token gesture and not enough. I seem to recall that he deducted $3 for 4 lots. I left him positive feedback which as I think of it, maybe I shouldn't have. In my case maybe I should have left NO feedback or neutral. In my situation though I wasn't that upset since the bids that I won were fairly low for the items to begin with. Adding the shipping to my winning bids I still got the cards for less than $1 a deck, including 24 decks of never used factory sealed Reserve cards. Mention the refusal to combine shipping, or at least discount, and, would mentioning the $17 s/h for a $1.70 postage be appropriate? At the time of bidding, I was unsure of the total impact of my shipping on the cards as I did know going in that cards are heavy. Especially 48 decks. Considering how quickly I got the cards and the fact that he didn't get cheap with his shipping methods and packaging and the fact that the end price was fair, I was willing to let it slide. That is the judgement you need to make. I will point out though that when a seller has a high shipping rate figure that into your bid. Don't bid as much. As I did I made sure that all costs were going to lead to a fair price in the end.

Further I would as you said in suggestion 3, not buy from him again. I mentioned in the feedback about the cards that I would consider the seller again. I would note that his quoted shipping for one lot of cards was pretty fair. However, as is often the case, sellers don't actually realize that shipping prices can plateau where 3, or 4 lots, especially with chips, cost the same as 1 lot. I can't remember the number but I think I have heard that it costs the same to ship 1 chip as it does to ship 6 or is it 9 chips. Then you can expect a slight increase for the next so many chips.

As is the case with the cards, I think the price hits a MAX level at some point where there is no increase for any more, other than the point where they would get too heavy for USPS.

To me though a bubble mailer with all chips in it and NO INSURANCE for $1.70 when you paid in almost $17 is a bit of a difference.