If it was a good customer, you must have evaluated the new site as soon as he had done. If you have been doing this for 10 years knows that most webmasters are masters of nothing more than quick cash. A few minutes with Google Analytics, see source code and a link checker that have prevented the 6 months of a poor performing web site.
it doesn't matter page, it matter according to your contents your content less then 200 you only use 3-4 keywords, less then 300 you use 5-6 keywords so you put keywords according to your contents. That's all dear
For best seo result use only 1 keyword per page. And your keyword must not repeat itself more than 3 times. But you can use variations of your keyword.
Putting too much keyword in your content this is a black head method mostly did for ranking boosting but if one's it read by Google then you have to pay lot's for this. Or more you can be permanently banned for SE. Some times it happens with some of my friendzz sites. After panda update it more necessary that you need to submit great quality content with less keyword stuffing. which is actually good for your site ranking.