Well, first of all, sales assistants are working on a commission and manager do ask them to push certain products. However, that does not mean that the girl you asked is not telling you the truth. Contrary to the some here on Basenotes I actually believe that SA are decent people just doing their job. They can actually give you an honest opinion.
On your second question.. Perhaps the only tendency I have noted is that some women are not that crazy about woody heavy scents and actually like sweet, floral and fresh scents on a man. IF he smells clean, then he's got some appeal. For each scent you do not like there will be a group of women that will love it. Kouros, Amen, Polo Green, Joop, Aqua di Gio, Dior, CK one, Happy, Old Spice...
A scent I do not like but many people love is Cool Water. Envy too.
scents I like but many people do not Black Aoud and YSL pour Homme, M7.