Living an INF-neutral lifestyle

Except influence and infamy trade on a 1:1 basis now. All publicity is good publicity.

What are these i20 major inf sinks?

That's only true if we ignore other means besides market fees for removing inf from the system. The OP lists a bunch of them. For x Inf entering the system we could actually destroy it all without a single market transaction by converting it to prestige, deleting the toon, etc.

A more accurate statement would be that x Inf entering the economy takes at most 10x in market transactions to destroy.

I am almost certainly inf positive, for many of the same reasons. I play the game on high settings, including large team sizes, even when solo. Worse, I actually bring my 2nd account in the mission, meaning that, though each character is getting a split of the inf, I trigger the team size bonus, increasing my total inf/time. I typically clear most maps of all foes. I, too, increased my difficulty when I got a level shift. (My characters are designed to operate near their performance edge, so dropping the level of all my foes defeats the purpose of having my characters built that way.)

I act primarily as a producer to the market. I don't "marketeer" - I just sell what I get that I don't want and buy only what I do want. Therefore I am not a good source of large scale inf destruction. I do currently craft level 45/50 commons, which destroys some inf, but I am only doing that for badge progress, and as each level 50 character gets all the badges, I stop doing it. (I want the recipe slots.)

I also don't avail myself of any of the newer inf sinks. I don't convert Reward Merits into Alignment Merits, because I earn reward merits so fast I don't often feel the need to, despite the ostensible efficiency increase in doing so. Consider it the merit version of spending 100k on common salvage. I consider it unlikely I'll want or need to make use of any of the inf sinks in the coming incarnate system, and certainly had no need to craft Notice of the Well components using cash.

Edit: I do think it's kind of nuts to worry about deflation at the level you mention. I don't think the mechanisms to allow that to happen exist. We produce so much inf/foe at 50, with such a low probability of an item drop per foe, and so many of us are playing at 50, I just don't see it at all.

For the Incarnate slots (both the alpha slot and the new ones you will get an option to upgrade the basic incarnate components (shards and threads) to rare/very rare components but doing so will have an Inf cost associated with it (for the new slots it totals 1 billion to get enough for a T4 boost).

However this is not the only way to get the new boosts. In fact I would even go as far as to say it is the least efficient way of getting the new boosts. The thing is that in order to get a T4 boost you need 1 billion Inf plus 2480 Incarnate Threads. If you do the incarnate trials (which are the best source of Threads) by the time you have done enough to buy the T4 boost you'll have enough Empyrean Merits to get it for no inf cost. The only people who are really likely to use it are people who don't do the trials and instead spend their time grinding shards to up-convert. As such I don't think it's going to have a major impact on the economy.

Actually the opposite would happen, if I take your meaning correctly. The purchasing power of your inf would increase, while the value of your stash of IO's would decline.

I think Enyalios means that her bids out currently would fill then be worth less than she paid. The Hoard is inf in storage. Maybe.

That's how I read it as well.

"Within 1%, x inf entering the economy takes 10x in market transactions to destroy?"

Perhaps you'll notice the phrase "simplified way to look at this" in the first line of my post.