Certainly there is no dearth of good launchers on the market but another launcher isn't going to work if you like touchwiz and want to use it. This means making do with the limitations Samsung gave us or modding it get options like changing the default grid.
To the OP, you should install another launcher even if you wish to use touchwiz. If there is a backup launcher to go to the phone will do it automatically if the default launcher stops or has other issues. This will give you a working device immediately to see you through till you can go back and sort out the phone after the fact, get your data off of it, etc.