Also having some kind of interface for users to sell and buy TC through each other should make it possible to collect an average rate for USD to TC and use that average for Nabi to sell TC at a competitive rate so users can benefit if they sell below average for a while but Nabi can attract purchases by offering bundle deals or something along those lines, don't really know for sure what to do with this issue.
I've brought this exact idea up with staff before - It wasn't super well taken, mostly due to concerns with increasing the TC/USD rate more than it has already, the fact that booster sales are actually fine and are much more reasonably priced, as well as sinking the spawned TC.
But, I do think this is honestly a really good idea and could actually bring Nabi in as a decent seller for TC. It just needs to be fully fleshed out as an idea first, with a set plan for pricing procedures so there isn't any risk of forcing players to sell at cheaper and cheaper rates.
I also generally feel positively about your other points, but Smaguris does raise a good point when he says that TB might be beyond saving.
Another point to consider is that staff don't actually get any of the returns that might come from brainstorming and pitching new revenue ideas. There's zero incentive for anyone except one specific person who is already very busy to spend any time at all thinking of ways to get Nabi more money. Which is probably why it never comes up, and there haven't been many significant attempts at it (besides a notable few, e.g. 3d item customization).
If enough good ideas were thrown at higher-ups, and were pushed enough that they weren't forgotten, I can see change happening, though.