I live in NYC and work in Times Square. It is totally doable. I'd be happy to help in any way I can, so please feel free to PM me if I can offer any advice or assistance. The only thing I'd say is that to/from LaGuardia to midtown requires more than an hour. He could take a bus right from LaG to the Port Authority and walk two blocks across town to Times Square, then on to 42nd and Fifth for the library which is quite nice and then 9 blocks across Fifth to St. Patrick's and Rockefeller Center. New York is safe, easy to navigate and fun.