People usually completely finish their website and they can do something else. Many people do a lot of decoration and mend to finish their website at once. Maybe they're thinking if the visitors see their website and it's not good enough they might not come back again!!! From what I've mentioned this must takes too long for the launch of website also made some information outdated or information update must be needed in order to the new launch of website.

From my experience a good website is a website that needs a maintenance and improvement all the time. All the information and decoration needed to make the website up to date and looks fresh all the time.
So I don't think the initial version of website should have all the information. All additional information can be added later. Moreover you can receive comment and suggestion from the visitor to improve your website. If you want a quality website, the website will always need an improvement and the development will not be ended. This is because if the development is ended then it's mean the website also ended, dead, too.

Another important reason is an updated website will be tracked more frequently than the non-updated website by the search engines. The more updated the more prioritize in order by search engines. The search engines will get back to the updated website more frequent than the non-updated one. So if you have a lot of information to show in the website but not urgently to show them. I'm recommend to separate them and upload on website in more frequently manner not in a big batch. If the information that you post onto the website is common information that everybody can read anytime they want then those information doesn't need to be removed from your website, just put it there and let the search engines do their jobs. This will add more opportunities for people to access your website.

There is also a question about the frequency changes of design, theme and color, of the website. From this question I would recommend not to change the design too often because you will make the visitor couldn't remember your website or your website will not looks unique. If you design to choose which color then just use that color for an amount of time. This involve the memorize of the visitors for long term. Think about how can you make the visitors feel that they're coming back to the same website. In the world of internet, one character might bring them to another website!!! Just make sure that you always update the information on your website to be up to date and link to the current situation. From all the mentioned above your website will be a lively website and ready to go to the online world with no shame on anyone.

I might need a strange wish for you today, “Hope your website will not be finished”!!!