No – I don’t think you are paying too much, it seems reasonable to me. As a comparison, I am in a two building scheme of 9 units, built in 1932. My levies are over $10K a year. Now this might sound exorbitant, but when a building is nearly 100 years old it needs a lot of work.
The agent fees don’t seem excessive.
You don’t say whether the owners have done a capital works plan to project what works may be required in the future. When you set the budget you should consider why the admin fund is now negative and whether you need to adjust the budget accordingly, and/or go through the admin amounts line by line and determine if they should be reconsidered.