Whatever you do you will always be limited on how much computer power you have yourself, and how well it "will" perform plain off.
But there's always changes you can do to make it run faster or smoother, at the cost of the looks of the game of course. I'd suggest you to read this
http://feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=10423.msg144855#msg144855Since it explains on how you can modify the game settings to make it less demanding on your computer. But some of the crashes will still occur due to the game that FeralHeart is. There's many things you can keep in mind to reduce your chances of crashing, but honestly, it can happen randomly when you are just sitting in a map doing nothing if you are unlucky.
If you read the thread regarding the whole core changing in the member made tutorial boards here
http://www.feral-heart.com/index.php?option=com_jfusion&Itemid=2&jfile=index.php&topic=11278.0I can suggest you to read it through and instead of using the commands suggested. Use this
C:\Windows\System32\cmd.exe /C START "FeralHeart" /d "C:\Feralheart" /high "C:\FeralHeart\FeralHeart.exe"
Since it puts higher priority on the game. But you will always, be limited on how much work your computer "can" do, and it's hardware in it.