WARNING - I am real concerned about have that many wires in what I think is a small area.
Can't tell from the picture, but typically there will be a LITTLE cover that goes over the area.
The space is not designed for that many wires and with the brittle insulation forced into the space more will break off and short.
Also does the fixture call out the requirement for using high temperature wire (90C). Many lights have this requirment. Don't know if fan/light units typically have this requirement or not.
If there is accessable attic space above this I suggest put a junction box in the attic and making all of your connections there.
Then run a single 3 wire cable of modern NM-B (sheathed electrical cable) to the fixture.
If it is not accessable then get an electrican in.
All that said, back to your question of the wiring.
First you need to verify which is the hot and neutral.
Get an extension cord that pluged into a known grounded receptacle.
Then using something like a $1.79 neon light voltage tester (or voltmeter if you have it) measure between the ground on the extension cord and the each wire on the income power cable. On the hot you will get a bright light (or 120+-5 volts) on the Hot and no light (or zero) on the Neutral.
If you measure any other voltage or have a dim light then you have other problems.
Then, as a test, connect the income power to just those that you think supply the other lights.
If those light don't work then you have other problems which might be identifying the wrong cable. With none of the wires connected and the power off, turn off the switches for the light and fan. and turn on the switches for the downstream lights.
Then using an ohmmeter the wires to the switches will read infinity or very high (in the thousands of ohms) (if you have lighted switches). The wires with the downstream lights will read a few hundred ohms or less depending on how many lights are "ON" and what size.
Now to wire the switches.
As you describe it you have switch leg wiring. Verify that by looking at the swtiches. You should have one cable connected to each each switch and nothing else connected to those cables or the switch.
This shows the basics for switch leg wiring.http://www.selfhelpandmore.com/switch-outlet/basic-light-switch/single-switch-power-source-at-fixture.php
In your case the incoming power hot anc neutral aso connect to the outgoing cable.
And you will have the "whites" (remarked black or red) of each switch connect to the the incoming hot.
The neutral from the fixture connects to the combined incoming/out doing neutral.
And the switch hot from each switch connect to the fan or light hot.