USA SPOT & FUTURES markets

1 Differences between FUTURE and SPOT markets?

2 Is there a chart that allows one to view MAIN USA stock-exchanges at a time?
(eg. S&P, NASDAQ, DOWJONES etc.) Please provide the url.

3 What is the market which shows the americans ringing the bell at 0930amEST, before trading commences? Is it S&P? What time it ends ; 430pmEST?

4 USA Futures markets are opened from when to when?

5 Which is more difficult to trade- USA STOCKS or forex?