Jerky preloader + updating site

Hi all!

please can you guys check out

it is very much uynder construction at this stage - if you notice the preloader that displays percentage - is very jerky - how can i make it smoother?? rather than jumping from 40% straight to 80% why does it not flow through all the numbers - maybe I’ve done something wrong?

Also if someone looks at my site and I later i change the bground colour of the HTML file if the same person looks at the site again will they see the new colour or will they only see it after deleting their temp internet files? As i remember having people test the site then making a change and having it re-tested but being told that there were no changes - upon me telling them to delete their temp files then they saw the change.

Hoope you guys are able to help me out