These points were all discussed above, but it's possible that money is not needed on Earth/federation planets, due to material abundance, but that money still exists and has owners to transact off-world. Jobs are not necessary, but could be paid in currency for such off-world transactions. So there are supply-demand forces at work to deal with scarcity. There are many possible ways the federation makes money (by transacting with non-federation systems), so the money they have would be valuable and could be used to pay for (federation) jobs on earth. This currency then gets used in the underground, but perhaps not necessarily illegal, economy.
People have different priorities and will work for free because of intellectual stimulation/enjoyment. There are still going to be factors at play to limit the demand at Sisko's resturant (I don't think I've seen that episode yet). First of all, since there is such abundance, patrons can go to any number of restaurants and get exquisite food. Secondly, the wait will be different at different places, so will limit people. Thirdly, as has been pointed out, replicators reduce the demand for many things. Plus the money described above could be used (in addition to possible bartering).
The jobs that are not wanted could have been automated by robots/technology.
I do not think that Risa is a Federation planet, it always seemed like lawlessness. Are there any references that Risa was Federation?
Another possible idea is that there is actually money, only not in the way that we think of it today, hence all the references to "no money." Eg, imagine a digital currency that there is such abundance of, that no one has real need to use it. Basically anything that anyone wants/needs could be replicated. You have traditional ownership of land and material possessions, but of course people aren't such interested in these things, and don't really think of it as "theirs". They might have a bank balance but don't use it during most weeks or months. If people so freely distribute it to others, then it might not be considered as money the way that we do today, and , and when they say that there is no money in the federation, it just means that no money is required for actual government purposes.