I have no idea if this will help anybody, but I'll post it anyway.
I too had trouble with Dead Space. I own the game as a PAL copy and I'm playing it on a PAL Wii. I'd tried ripping the game numerous times, both using IOS 222 and 249, and the game would not work at all. I tried booting with CFG USB Loader and WiiLoad, and both had the same problem. Basically, the game would freeze during the intro logos and I couldn't even get to the menu. I tried the latest versions of both loaders with no success.
As a last resort I decided to clear my USB entirely and reformat. After that, and before installing the game again, I used the 3.0C release of uLoader's cIOS 222 installer to try some different mergers. Using IOS 249 in both instances, I installed Custom IOS 222 with IOS 38 merged with IOS 37, and the IOS 223 with IOS 38 merged with IOS 60.
I then used CFG USB Loader to rip a new copy of the disk, and I've managed to have it make it past the introductions and get the menus. I'm not actually using the Hermes' IOSs, but formatting my drive again and doing the above made Extraction load further than it has before with no crashes (cannot verify crashless gameplay though).
As I said, I don't know if this will help anybody, but that's how I've got to where I am, and I had it failing to get past intro logos :/.