New blog lite issue

Hello,

I just activated this wonderful theme.
It seems though that there is a huge space between the slider and the rest of the content. Is this because my pictures all have different sizes ?

Also in the footer it looks like a mess because off the different sizes, do I need to put the featured pictures all in the same size maybe ?

I am very new at website building, so I could use some help ??
thanks !

The page I need help with: [log in to see the link]