That's why I don't quite see how the money makes its way to Steemit Inc. to pay their development, api and full node costs

I think it doesn't need to if the Apps create their own nodes and Stinc can reduce their costs heavily. They can then also develop the chain to make it lighter to reduce node costs and then have some stream come in from the Dapps themselves.

I mentioned Steem-ua because of algorithms only but large advertisers would create their own versions, almost guaranteed.

So I'm not so sure on the advertising route at all, though it may be the one the community decides to run with just to keep things running at all.

I think Steemit.com should be killed off and let the app interfaces take over and monetize themselves enough to cover a full node cost at least. One of the apps could still offer the same interface as steemit.com and take a beneficiary for it.