Delays caused by their own systems or by government intervention in China will only drive up the price of phones which will again be bought outside their country and imported for resale, as was done before.
You don't know how acting as an agent to license and collect royalties could benefit Apple? That's "where the money is." Apple would cut out all the middlemen in the mechanical rights licensing business. That plus being able to put together so-called 360° deals which extend to other entertainment properties...there's a LOT of money to be made.
My (somewhat limited) understanding is that the consumer banking and credit industry in China is far less developed than in the West and Europe because most Chinese prefer to deal with cash. There are much larger black markets in China because of wide systemic corruption. I think Apple Pay is kind of a non-starter, unless you're just talking about its use as a debit card. Any attempts to undermine or circumvent Chinese currency or bank regulations will be met with...
The only way I can think of some benefit for songwriters would be in the way music is licensed. Perhaps songwriters will register their music through Apple and Apple will act as licensing and royalty agent, replacing BMI and ASCAP. Only by becoming a self-publisher of music (lyrics and compositions) do songwriters have any influence over the use of their own work.
The real money is in merchandising, touring and licensing music rights for advertising and entertainment. There is typically very little profit in the actual sales of music to consumers unless one has a massive hit. Why? Competition. There are thousands and thousands and thousands of people with millions of songs competing for attention.
I don't think Bono is interested in anything other than promoting his personal projects (which is fine, by the way...he's a business person also), so it's probably a benefit concert, U2-branded product, or cross-promotion for Product RED.