Hi newsoftw,
With XCache all you really need to do is tweak the memory allocations to the cache and var cache, var cache is the only one vB Optimise is concerned with, for Lite I'd recommend allocating about 30M (which is 30MB) - should be more than enough, the other cache is for php files which XCache does automatically, you can assign that to whatever you like depending on how much php you have on your server, 30M there too should be a solid value.
No other tweaking needed really, although the configuration does ask for your cpu count and it does give you the command to run to find out, so make sure that's valid and you're all good