Minecraft will run perfectly well on F14 without many modifications.
Just figure out which java you are running by using the 'java -version' command.
[user@localhost]$ java -version
java version "1.6.0_20"
OpenJDK Runtime Environment (IcedTea6 1.9.7) (fedora-126.96.36.199.fc14-i386)
OpenJDK Client VM (build 19.0-b09, mixed mode)
From there I just put a small script into the same directory where the 'minecraft.jar' file is located. I called mine 'minecraft.sh'. Just place the following inside the file:
java -jar -Xmx1024M -Xms512M minecraft.jar
Then do a chmod +x minecraft.sh to make it executable and invoke it with a ./minecraft.sh to launch the file.