Hi disenchanted,
There is lots of info on EOS on running a community and the following link should get you started:-
www.eyeonspain.com/spain-magazine/horizontal-laws.pdf
You can also search for the answers if you click the 'Search EOS' text at the top of this page (it's under 'COMMUNITY') .
One thing I do know about community fees is that the amount each member pays is calculated on the size of their property as a percentage of the total community (habitable area including terrace or patio) irrespective of whether they are resident or non-resident. Residency status has no bearing on the charges if you use it one week per year or 52 weeks per year the fees are the same.Similarly, apartment blocks with lifts usually ALL pay towards the maintenance of the lifts-even those people who live on the ground floor.
The fee each owner is charged is worked out as a percentage of the total costs to run the community. I.e., if your apartment works out at 12% of the total habitable area of the community, then you will be liable for 12% of the running costs.
Personally I would not be paying anyone anything until the community was properly set up and registered.
Until Maria comes along, probably on Monday and usually very early, I hope I have answered some of your questions and pointed you in the direction of some additional information.