Exjun,
If you are using 10.5 or later version, you could divide the elements across multiple subdialogs. These are like sub-routines and can make the application modular and then you o not have to worry of elements in a page.
See attached screen shot as an example.
You do not have limit on number of elements in a call as such.
Refer to "Element Specifications for Cisco Unified CVP VXML Server and Cisco Unified Call Studio" for more details.
Thanks