I pushed a load of pages live on my site last week and have just checked now and they have been indexed - still get sero traffic from google though overall
When you talk of Onpage Optimization changes. Would you consider a Major Change (one that will show a rankings change) to be increasing the keyword density of your targeted keyword from 3 to 3.8 percent , for example>
An increase in keyword density of 1% should do the trick. If you want to see real movement then change the terms the page targets to different ones.
One of the big cock ups in onpage stuff is the actual site structure and navigation structure/map on the page.