How to create a Photos and Videos Only wordpress site?

Hi! I’m developing my New site (naluguru.com) which is a Photos and Videos Only site with User generated content.Users can upload their Photos and share video Links.Since this is a photos and videos only site I have created two categories Photos,Videos.
My website details:
Theme:customizr
Plugins:
Broken Link Checker
User Submitted Posts-For uploading photos by the Users
Huge IT Image Gallery for adding photos in a Grid
Slideshow
WP Image Borders
I have included two categories in the main Menu.
I have created a single post without any name and added all the photos in a single Gallery and a slider for Ten recent posts(photos and videos).

i.imgur.com/11n2puk.jpg

Problem comes with adding videos to the Gallery.I’m unable to add any video links to the Gallery.
I want the Gallery to show my videos also and how to add new posts(photos/videos) in the Gallery so the Gallery shows recent posts first.
whenever user clicks on any post(photo/video) it should zoom in with Navigation facility for other posts.

i.imgur.com/ZmoH2U5.jpg

whenever user selects a category from the Menu.It should contain posts only for that category.
How to correctly add the posts so that I should not disturb the Order?
Since I’m adding all photos to a single Gallery will this effect Page loading?

Please help in Building my site.Thank You.

………………………Pardon my Grammar…………………………