Shinkansen (Shin-Osaka to Shinagawa)

Greetings,
I just purchased a ticket for a nozomi-class fr shin osaka to shinagawa. I live in Kadomashi, Osaka and the best route for me is to take the train fr:
Kadomashi --Kyobashi--Osaka-Shin Osaka--Shinagawa.
kadomashi to kyobashi is through keihan line. Kyobashi to osaka is JR-Inner loop and osaka to shin osaka is JR kyoto. 1) Since the ticket i bought (basic fare ticket), do i still need to purchase a JR basic ticket at Kyobashi to get to Shin Osaka?
2) It states that its valid for 4 days. Does that mean i could hop on to any JR lines without having to buy any basic tickets? for 4 days starting from the date of travel? Advance thanks for answering.

Since the ticket i bought (basic fare ticket), do i still need to purchase a JR basic ticket at Kyobashi to get to Shin Osaka?

If your basic fare ticket states Shin-Osaka as start station, then you will need to buy a separate ticket for the section from Kyobashi to Shin-Osaka. But if it states something like "Osaka City Area" as start station, then the journey from Kyobashi will be covered.

You could theoretically go to the ticket counter and change the starting point of your ticket from Shin Osaka to Kyobashi. I think it should be free, because there is no difference in price between base fare Shin-Osaka to Shinagawa and Kyobashi to Shinagawa.

It states that its valid for 4 days. Does that mean i could hop on to any JR lines without having to buy any basic tickets?

No. However, you are allowed to get off and on trains as many time as you wish along the route indicated on the ticket (presumably along the Tokaido Shinkansen). No backtracking is allowed. You will have to buy separate shinkansen supplements for each separate section traveled.

Thank you for answering!