You can have 1000 pages and never rank high for a single keyword. Or you can have 25 pages and rank in top 100 for the most of them. A lot of factors go into it, the quality of your on-page optimization, the quality of your backlinks, etc.
Quality counts, not number of pages. Sure google might index more pages (ie 300 of a 2000 page site) quicker but still wont care to return your pages if you have no authority.
It all depends on how you build your links even you have lots of pages. You can just pick some pages to optimized first to rank on search engine and later on the other pages.
No It's not .... Rather than increasing the page of a website... First promote few keywords per page and when it got some position then you can think of new one...
It is better to start the work with few important targeted keywords so that they can rank high in the SERP...It does not matter how much pages you have....
Position depend on keywords search volume and site structure. If keyword search volume is more then it'll take some time to get first page position. If you want quick improve ranking then your need first start on-page optimization and after that strong off-page activity.