the Home Button is the Main Button. It can't be subsituted.
Yes it can at 98%
1% will be to use it to take screen shoot.
1% will be to use it to perform the hard reset.
The rest of what the home button does can be replace by gestures using "MultiCleaner" from cydia. I'm using it all the time to open previously close app, to minimize an app, to close an app, to close all apps running in the background, to reveal the multiTasking bar and last to activate the voice command.
Look for MultiCleaner in Cydia, install it and open it and set up the touch gestures the way you want. Let me know how it goes.