Have you ever thought about how well Amazon converts? I don't think so. Do you know about threshold accounts? I don't think so. Do you know for how many days your cookies stay in a browser that will get you commissions from Amazon? I don't think so.
1) i hear it every time amazon gets mentioned. remember reading somewhere its usually between 0,5 and 1%? but i don't have the hard data and it surely its very niche and pricetag dependant. thats why i said "i see it as a difficult and frustrating journey" and not "this hard-earned statistical data proves that this journey is a bad idea".
2) anyone who has browsed the marketplace for more than 10 minutes knows of them, so yes.
3) i think its 1, with a 89 days extension for products added to the cart in those 24 hours.
If I research for you, then what are you doing on the forum?

I won't be ENLIGHTENING anyone. If you want to earn money, enlighten yourself. Otherwise, stay where you are now.
this is perfectly fine as you don't own anyone anything. but belittling others with rhetorical questions while refusing to fundament your point is a little awkward. even if you know better than others, remember this is a forum. we try to help and offer opinions, but there are no promises that we will all hit the nail each time. that's perfectly fine too, so lets keep it classy.
edit: to add a last point, i do agree threshold accounts are so cost-effective that they may make it work on sheer force of buying 600usd of advertising for 60 bucks. but since its THaccounts that will be carrying the whole thing, may as well use them for a site monetized with affiliate programs with better commissions. maybe i am underestimating amazon conversion or the 89 days extension, but i just struggle to see it being a better option than a program with good commissions. maybe it also depends on your target; some demographics may buy lots of random stuff on amazon each time they get on it (rich bored folks) getting full advantage of the amazon cookie, and some may only look for very specific stuff (young, broke folks?) rendering the cookie "product sharing" worthless, and depending on the niche you will get more of one or the other. that may be a factor too. but again, i don't have the hard data, so that's it from me.