Skins

Is it possible to display more than 15 items/posts on the front page?

Yes, off course it is! (I mean, Nucleus is not called 'most flexible blog tool'for nothing)

You can change the amount of items showed on the front page through the skin you currently use:

In the Admin area, click Skins on the left hand menu.
Look for the default skin (if you haven't changed the look of your Nucleus site since you first installed it. Things may be named differently if you modified the look of your blog). Click on the Main Index link.
On the next page, you can change the code that controls the look of your front page.

You have to look for this:

<!-- page content -->
<div id="container">
<div class="content">
<%blog(default/index,10)%>
</div>
</div>

The blog skinvar has two arguments. The first one, default/index, tells Nucleus that the default/index template should be used to format the items on the front page. The second one, 10, is what we are looking for. It tells Nucleus to show 10 items on the front page. Change that number to something you like better, and Save. Done!