Point 1 is clear and on the company's todo list for a long time, but 2 and 3 are not: Yahoo could create a new entity into which the web business is transferred.
I think it's safe to assume that they investigated every other angle as far as reducing the tax burden goes and this is the best they came up with (source: fiduciary responsibility if nothing else). Unless you have some inside info or reporting that says otherwise.
they tried that, and all the tax experts they could hire said they'd still get a huge IRS bill.
Not true: they tried to create an entity and move the Yahoo! Japan and Alibaba holdings in there, which had the perceived danger of a huge tax bill. They could create an entity to move the main business in, which would be taxed as much as the current deal.