A few coding changes for shopify website

We have a few changes we would like done before launching our Shopify website.
Requires Shopify coding knowledge

Jobs for website
-make top banner container fixed height
-"search store" improve styling
-URL structure
-change out of stock message on collection page
-Notify us if product is out of stock on website
-change "view all" links in menu to correct collection
-change image on mega menu for each collection