I have never known the JR Rail Pass to be valid on the Nozomi.

There are 7 Hikari and 3 Kodama departures from Tokyo to Kyoto between 9:03am and 12:03 pm, with the Hikaris every half hour. The Hikari is not slower than Nozomi, it just makes a few more stops, taking about 20 minutes longer for the entire trip. Not really much of a hardship.