a lot of answers depends on what your building code is. the information I'm listing is based upon the 2009 International Residential Code (your code may vary, and needs to be verified by the building department).
if you have fixed stairs to the attic then attic joists must be able to support 30 pounds per square foot live load plus the weight of building materials (typically around 5-10 psf). These shall be treated as floor joists. if accessed by scuttle or pull down stairs then 20 psf, if no storage storage (areas you won't be walking around) then 10 psf. You can view the ceiling joist span tables from this code here
http://publicecodes.cyberregs.com/icod/irc/2009/icod_irc_2009_8_sec002.htm
I agree with Brock, wall #2 appears to be load bearing since a 2x6 ceiling joist cannot span 22' to 23'. I'd expect the joist to be able to span around 12' to 13' (depending on species and grade of 2x6) based upon a live load of 20 psf. Also because of the location of wall #2 in regards to the basement stairs. Is there a beam in the basement under wall #2? Is there a beam under wall #1?
if you remove a load bearing wall without proper support of the attic/ceiling joists then you could experience excessive deflection of the joist which could cause cracking of the drywall/plaster ceiling and potential damage to the joists themselves (depending on actual loads).
Post back with answers to the questions and I'm sure you'll get responses.
Good luck!
