I would do the following:
1. Run a single 14-2 to master bedroom and run the overhead lights for the closet and bedroom on same circuit.
2. Run a single 14-2 to master bedroom and run to the receptacles
3. Run a single 14-2 to second bedroom and run the overhead lights for the closet and bedroom #2 on same circuit
4. Run a single 14-2 to second bedroom and run the receptacles, then extend it to the 4 receptacles in the hallway.
5. Run a single 12-2 to the jack and jill sink. A 12-2 is sufficient to run two hairdryers at the same time on a 20 amp circuit. Add a GFCI at the receptacle (you could add a GFCI circuit breaker, but you don't want to walk downstairs to reset the GFCI when it trips).
6. Run a single 14-2 to the jack and jill bathroom for the bathroom light/fart fan. That way, when you turn the hairdryers on, the lights don't flicker.
7. Run a single 12-3 to the fire alarms and daisy chain them using the red wire as the alarm wire. Down in the panel, the red wire won't be run to anything. Just cap it. I would put one smoke alarm in each bedroom and a CO detector/smoke alarm in the hall. Be sure not to put the detectors near a supply air vent (if you have HVAC). You can't connect this circuit to anything else in house other than smoke alarms. I used 12-3 because 14-3 is hard to find.
You may be saying--gosh that's a lot of wire. But think about it this way--you are saving a TON of money by doing the work yourself, and you'll never to have to worry about overloading your circuits. If you want to do it on the cheap, you could get by with four circuits instead of seven (#1-bedroom #1 and #2 lights; #2-bedroom #1 and bedroom #2 and hallway receptacles; #3-bathroom sink GFCI and lights; #4-Fire alarm). Note: I never put the receptacles and lights on the same circuit--flickering lights from the vacuum drives me batty).
Circuit Breakers - besides the one GFCI near the sink, all the bedroom circuits have to be on AFCIs--fire alarm too (2005 AFCI requirement applies to all 15A and 20A branch circuits in bedroom areas--receptacles and lights.)
If you are getting a new panel, be sure it's a 40 position panel.
As long as you are pulling wire, consider running coaxial and CAT5e/CAT6. A wired house is worth more money, plus wireless speeds suck.
When I re-did my daughters bedroom, I also ran new wires and alarmed all the windows (no sneaking out....of course she's two right now).
As long as you are mucking around in the attic, do you want to run wires for any exterior flood lights?
As to running the wire loosely over the finished ceiling, I recommend you secure it as much as possible. I've been told when running wire into an enclosed cavity that you don't have to secure it like they require when its opened walls and you can do it (they realize you can't staple within the closed wall cavity). But ask your building inspector.
Receptacles - use the new tamper resistant receptacles and secure the wiregoing in/out with a staple 12" from the box, then every a minimum of 4-1/2 feet. Oh, and if you drill the studs, the wire through the hole is considered secured.
Light switches - replace them as long as you are rewiring.
I would also replace all of the receptacle and light switch boxes with new, larger boxes--easier to work with and you'll never have to worry about a fill violation.
Finally, consider adding a fire escape ladder (I got this PEARL one--it tucks in right under a window) Fire Escape Ladder | Permanent Escape & Rescue Ladder | Home Fire Escape Ladders
I'm not an electrician, just a well-read DIYer.