For Data Import 8 MB limit we can update the value for ImportMaxAllowedFileSizeinMB in ServerSettingsProperties table in MSCRM_Config database.
nishantrana.wordpress.com/.../the-import-file-is-too-large-to-upload-error-while-importing-csv-file-of-more-than-8-mb-in-crm-2011
For auto loading all the subgrids blog.customereffective.com/.../crm-2011excessive-sub-gridding.html
Excellent. I have read a good article today