Bern Oulli,
I agree with your chosen selections, plus if I were doing the cleaning I would add these as well,
O18 - Protocol hijack: cn - {9346A6BB-1ED0-4174-AFB4-13CD4EC0AA40}
O2 - BHO: (no name) - SOFTWARE - (no file)
O2 - BHO: adlog Class - {22B9A67D-E689-44B6-B775-0E8FE84B4F9B} - C:\\WINDOWS\\system32\\hiauygd.dll
O2 - BHO: Setup.Setup1 - {2E65A557-173C-4DE9-860B-28FC5CACA542} - C:\\DOCUME~1\\ALLUSE~1\\APPLIC~1\\Setup\\Setup.dll (file missing)
O2 - BHO: BHObj Class - {8F4E5661-F99E-4B3E-8D85-0EA71C0748E4} - C:\\WINDOWS\\wsem303.dll (file missing)
O2 - BHO: BHObj Class - {F7F808F0-6F7D-442C-93E3-4A4827C2E4C8} - C:\\WINDOWS\\nem218.dll (file missing)
O2 - BHO: SDWin32 Class - {FD899702-326F-4B46-9906-6BC5D4FADC0F} - C:\\WINDOWS\\system32\\vyosj.dll
O3 - Toolbar: (no name) - {BA52B914-B692-46c4-B683-905236F6F655} - (no file)
Anything with no file or file missing cant hurt, and I have a big distrust for any file names that dont spell anything or look like a shorthand for something.
You are a brave man for tackling something this bad. good luck.
The worst that could happen id that you end up having to do a complete rebuild. I hope the pay is good, or at least the beer is to your liking.