Look at admin/configuration/indexlisting- set new products on main page to 0. This should remove the new products centerbox from the main page. Same for featured,specials, and upcoming, meaning set those values to 0 if you want them gone as well.
Look at admin/configuration/maximum values and try setting random products for sidebox to a higher value. I am not familar with scrolling new products sidebox, so I don't know if this will work. If it doesn't, you might try admin/config/maximum values new products module, and set that value higher.
Also admin/config/maximum values new product listing limited to determines the lenght of time a product is considerd new.
Good Luck
