A detailed summary CWOT and finally you asked
What are some other dynamics to AQ donor support that I have overlooked?
At times you infer Gulf donors act as investors in the Global Jihad cause, via AQ Central. That is a good model to follow in part.

The AQ Central prospectus is quite clear: we are engaged in a relentless struggle, attempting to mount "spectacular" attacks - with allies / partners and have a long term strategy of antagonising our enemies into action.

Revenge IMHO is a particularly strong factor for those whose participation is only as an investor. All too often we forget terrorism is armed propaganda. AQ Central appear to have a more effective global PR appeal and infrastructure than the others.

AQAP gain much from the US focus and fear of them (that is another matter).

Donors appear to trust AQ Central, after all the relationship is far older and may date back to the 1980's. Once committed as donor how do you stop? Plus I would expect AQ Central has to endorse other groups before investments are made.

The scale of the donations is quite small and somewhere I recall reading a few years ago US$30m was the annual estimated amount AQ Central needed.

Finally fear of discovery for the donors by their own governments, who take action, not issue "coded warnings" and publicity. Given the apparent ease of making donations for many years without discovery and publicity I have a low expectation that donors are concerned with Western attention.