Right. Do what Vulture and derringer3 said and it's also a good idea to install SystemPatch right after FBlit. This will save you many KBs of chip ram.
If you have OS3.5 you can use the WBCtrl command with the right arguments instead of workbench prefs.
2. Is there a way to 'patch' some fastmem as CHIP?
There are some patches which do something like this but they are hacks and cause problems like loss of sound. MemPatch of MCP is one of them.
