1. Is there enough to interest a 7-year old, beyond the ship's kids program?>>
It depends on how many more children his age are on the ship. The ports are very interesting and colorful and would capture the interest of a 7-year old.
<<2. We would be traveling in late August - how cold would it be on deck? I have heard that the mosquito is the state bird of Alaska - how bad is it really?>>
It won't be so cold, but expect lots of rain. late August/early September are the rainiest periods of the year. It is still very enjoyable, however. It is the most prolific salmon migration period, so you will see lots of salmon. Your son will love it.
<<3. For kids programs on Alaska ships, would you recommend RCCL highest?>>
Without question. Don't even think about another line. HAL, Princess, Celebrity, NCL and even Carnival are going to have an older crowd on them.
Have a great cruise and let us know how it went.