1. There are 04 Slide Effects. The First one is Flash Slider. Rest of the three are JavaScript and HTML5 based Slider. You may try them
2. You can apply This Technique for such these Styling. Your logo image itself smaller. You can use larger logo and can use this in the Custom Code within Head Area Box of Simplify Options
<style>img.site-logo, .site-title { max-height: 70px; max-width: 250px; position: absolute; }</style>
3. You can change the Text “Our Service”. You can also set the 2nd Featured Boxes as 1st style but First one can’t be styled as 2nd one. You can change the position customizing the featured-box.php file
4. Customizer is not a Part of Theme. That is WordPress Core Feature. You can add any style css in the Custom Code within Head Area of Simplify Options using starting <style>
and closing </style>
Tag. Find more in Ans: 2
5. Please find the Ans: 2 and 4
Thanks