Is ist possible to add some new Modules to the bottom-modules?
I added in the config.xml


<rows label="Position">
<row>top-a</row>
<row>top-b</row>
<row>top-c</row>
<row>top-d</row>
<row>bottom-a</row>
<row>bottom-b</row>
<row>bottom-c</row>
<row>bottom-d</row>

<row>bottom-e</row>
<row>bottom-f</row>
<row>bottom-g</row>
<row>bottom-h</row>


And in theme.php like this:

<?php endif; ?>
<?php if ($this->count('bottom-e')) : ?>
<section class="<?php echo $grid_classes; echo $display_classes; ?>" data-uk-grid-match="{target:'> div > .uk-panel'}" data-uk-grid-margin><?php echo $this->render('bottom-e', array('layout'=>$this->get('grid.bottom-e.layout'))); ?></section>

Is this the right way to implement new modules? Or must be done something else?

Yes you are right, but you need to add the new modules to:
layouts/ widget.php
Here is a more detailed documentation: How to add a module into Warp 7 framework:
yootheme.com/themes/documentation/developers/widgets-2