Skews the chart grid in a logarithmic fasion. This allows it to display more graphical definition of the most recent varience. If multiple symbols are entered and Show Spreads is not checked, the main chart will display the percent change for the duration of the time period selected.
Events shows at what point the split occured and the ratio of the split.
During market hours, intraday price action is in the context of daily historical market data. Instead of a closing price, however, checking Intraday Price Action box shows the last quote price. This feature is especially valuable for spotting breakouts, bringing together the best of both intraday and daily graphs. However, you may find that charts without the Intraday Price Action are a little faster, especially if you're using a slower Internet connection. A green Intraday Price Action indicates the last price is higher than the closing price of the previous day.