You should overwrite the 40% max-width for the entry-container class.
#featured-slider .entry-container {
top: 50%;
-ms-transform: translateY(-50%);
-webkit-transform: translateY(-50%);
transform: translateY(-50%);
position: absolute;
left: 5%;
max-width: 40%;
}
Copy this piece of code to the CSS Editor after the change.
I will look into your second question too, because I also want to change the standard slider appearance. I’ll let you know.