Yes, your dues pay for the personnel who work at the resort and any of their benefits, and that includes housekeeping (usually the most expensive item service item), front desk and other personnel, maintenance personnel, and security. You also pay for transportation systems -- busses, boats, and monorail -- and their personnel to extent your resort uses any of those. Personnel costs are about 65% of all your dues.
As to "full" cost, that depends. For example, those at OKW would pay the full cost or close to it of their front desk personnel but those at BWV share that cost with BWI. BLT members pay only a portion of the monorail costs since it is used by others.
Your dues also, of course, along with those from all resorts pay for Member Services although in a round about way. There is $1 per member reservation fee that goes to MS. Then there is "breakage period" inclome. At 60 days or less out, DVD can rent any unreserved rooms. The net income from those rentals goes first to offset up to 2.5 percent of the resort's operating budget. Then amounts above that go to pay for MS (and if amounts exceed what is needed for that, it goes to DVD). The third potential source for MS costs is the Management Fee. It is an item listed in the dues and pays for Disney's overall management of the resorts and anything additonal needed for MS and its reservation systems. It is a set percentage (12.5%) of the annual operating budget of the resorts. The percentage does not change buit the amount goes up as the total dues go up. Much of that fee is mostly real (and legal) profit for DVD. It is the incentive that keeps Disney from selling a sold-out resort such as VB or HH.