We did the west coast last year and loved it!
For vegas I would only stay 3 nights, I wasn't the biggest fan I found it seedy and didn't like the smoky/seedy atmosphere in the older hotels (treasure island, harras, the quad, flamingo, Luxor, mirage). BUT I am really glad I went exploring the hotels is fab, as are the shows and dining.
Like others have said I would totally recommend staying mid strip, we also stayed at the elara connected to planet hollywood and it was a fantastic location to get around. The elara was lovely with no resort fees.
We saw david copperfield which was amazing and I would totally recommend the wicked spoon for an awesome buffet!
Disneyland is amazing! Lots of reasonably priced hotels across the road from the parks, we stayed at the disneyland hotel (treat for my 30th) but honestly no need too, as the offsite hotels are just as close.
In LA do the warner bros tour, that was awesome. We also saw a show at the El Captain theatre in hollywood that was really special.
My favourite place was San Francisco, loved it! Could spend a week there easily. If your doing alcatraz get your tickets early as they sell out months in advance.
Let me know if you have any questions