Having started with iClone 1.52 myself, I have imported iClone 1 characters into iClone 5, so they could still be used. Motions could be used too, but some animations may be a little off when applied to newer characters. Props should work regardless. No reason to throw anything away if you have a use for them.
If you run Windows 7 now, you may have problems installing and running iClone 1, I wouldn't know. Perhaps XP compatibility mode would help then. BTW, iClone 3 or 4 is a good bridge between older content and iClone 5.
Don't worry about being slow... And welcome back!