As a general rule, Google will index more pages the higher your PageRank is, but I don't know what those numbers are.
There is no limit as such. All your website pages should be easily spidered by the Google robots and there should be no duplicate content present in there. Web pages that have a higher Page Rank tend to perform better in search engine results. Therefore its best that you have a flat structure for all the files rather then stacking them up in multiple levels. All the HTML tags should have a unique title tag, Meta tag description etc. Have a nice day!
As for me, there is no limit on how many pages you have... In fact, it will be a good factor for you as you added NEW pages with NEW content. SEs (especially Google) will love it.