1) yes it is recommended to switch very slowly. 2) i used rice right away because neocate is soooo thin and my son choke on normal formulas as it was so i knew he needed it thickened. or i have some simply thick samples if you are interested.
babies under 3 months have the most success in regards to accepting the taste. our ped said that babies older than this have sort of established their taste buds and may reject it..