Step 1: on your app/code/local/Technooze/Tcatalog/Helper/Data.php file add the below code which is copied from app\code\core\Mage\Catalog\Block\Product\Price.php and modified slightly to suit our need.
It's quite easy to display magento's sub-categories under top level category page. I keep loosing the previous work, so i am writing here so i can find it faster next time. And, You can use it too if you want to :) Any suggestions is welcome.
Add below code on file: catalog/navigation/sub_category_listing.phtml
So, far I know Magento e-Commerce has no support for image resize other than those for product images. But no need to fear as we can use same image resizing object and customise it to suit our need.
Just follow the following post and you will have image resizer in fraction of time you will spend on researching and writing your own as i had.
Create Folder named "Technooze/Timage" under app/code/community