Weekend is a MUCH better time to visit Waikiki. The traffic going into that area in the morning and the traffic leaving that area in the afternoon is crazy during the weekdays. So, unless you are planning on sitting in traffic for at least 1 hour, don't go during the weekdays. You can avoid this traffic by leaving Aulani after 12pm, and not returning to Aulani until after 8pm. But if you are heading into Waikiki between 7am and 10am, it will be very, very full of traffic. I've sat in two hours of traffic before, trying to get from Waikiki to Aulani in late afternoon, it's not fun!
Also, as stated above, Aulani is much more crowded on the weekends, as many locals get rooms and enjoy the facilities.
And finally, I really enjoyed the Swap Meet once my husband finally talked me into going to it. I think it took until my 5th trip to finally go, now I try to include it every time we visit. Great prices for all the souvenirs you see in the stores in Waikiki.