Was Google Keyboard preinstalled on the phone, or only the Samsung Keyboard? If you had to install Google Keyboard yourself, then you have to reinstall it from Google Play Store, since a factory reset wipes out all apps except the preinstalled ones. The same goes for Big Buttons Keyboard.
As for other issues--try wiping the cache partition, which won't erase any personal data:
http://support.t-mobile.com/docs/DOC-5744.
If you have a microSD card inserted, try unmounting it (in
Settings>Storage), removing it, and rebooting. A corrupt card could cause various issues. To check the card, insert it into your computer's SD reader and run chkdsk:
http://forums.androidcentral.com/amb...d-sd-card.html
You could also go to
Settings>Accounts and try removing your Google account completely, then add it back again.