1) You can't set your SD to be default location (for apps) if your phone is not rooted. (i will not advice you to root it for that problem...)
2) You can transfer your apps and data to your phone right? ( http/www.tomsguide.com/faq/id-2908201/move-apps-card-... )
3) Download CLEAN MASTER! This app will give you enough space to handle most of the games you want (use it wisely. clean your phone once per week or month).
4) Uninstall every unused apps! Some of the stock apps are locked on your phone... uninstall their updates and lock them out!