Remove space from Blog post body and Footer for Blogger

Add code to CSS

.main-inner { padding-bottom: 0px !important; }

Show widget only in Homepage for Blogger

In Template click Edit HTML and edit code below;

<b:widget id='HTML1' locked='false' title='Recent Posts' type='HTML'>
<b:includable id='main'>
<b:if cond='data:blog.url == data:blog.homepageUrl'><!-- only display title if it's non-empty -->
<b:if cond='data:title != ""'>
<h2 class='title'><data:title/></h2>
</b:if>
<div class='widget-content'>
<data:content/>
</div>
<b:include name='quickedit'/>
</b:if></b:includable>
</b:widget>