They absolutely could and more importantly for their purposes is that they could invite powerful people not for mere money but goodwill and favors. Laurelorn is peaceful in a way no human city can be, it is a place of magic and...
I just thought of something. Way back in the thread, thousands and thousands of pages ago we had a conversation on whether the Emperor could command the Jades to extend his life, the conclusion was no in practice even if he had the power in theory, too many of the movers and shakers of the empire are distinctly uninterested in the prospect of an immortal emperor.
That is not to say the elves could hand out immortality either they would face if anything a worse backlash if they tried, but if some elderly nobles happen to come to Tor Lirael as tourists and come back 'feeling five years younger', well that just means they had a nice relaxing stay right? Not saying all or even most high nobles would go for this, but even a handful in the right place could be very valuable to the Eonir, enough maybe to set up that tourist industry as cover.
[X] Plan Bring Running Shoes with Seviroscope; Ranald brand footwear.