The popup sizes can be changed in the views which are calling the popup.
For example, the add/edit address in the user control panel use the view "address / lisitng", you can edit this view and change the width / height values in this code:
<?php echo $this->popup->display(
'<img src="'. HIKASHOP_IMAGES.'edit.png" alt="'. JText::_('HIKA_EDIT').'" />',
'HIKA_EDIT',
hikashop_completeLink('address&task=edit&address_id='.$address->address_id.'&Itemid='.$Itemid,true),
'hikashop_edit_address_popup_'.$address->address_id,
760, 480, '', '', 'link'
); ?>
width: 760, height: 480
For the image zoom, are you talking about the zoom on a image in a listing ?
If it is, you can edit the desired view (generally product / listing_img_title) and edit the line:
echo $this->image->display(@$this->row->file_path,false,$this->escape($this->row->file_name), '' , '' , $this->image->main_thumbnail_x, $this->image->main_thumbnail_y);
And replace "false" by "true", it's working this way for all the thumbnails.
Concerning the space between currency code and amount, you can edit the currency via the menu System > Currencies.