I wouldn't bother with replacing the keys unless they are damaged (very unlikely). Timing marks on the belt and the pulleys make alignment easy. Just be careful with the torquing the bolts as the entire engine is aluminum! Torque values are EXETREMELY low compared to the cast iron lumps (Ford and Chevy) I've worked on in the past. The EG33 engine is an impressive piece of machinery when disassembled. The machining work is amazing. The cams ride directly on the aluminum saddle, NO BEARINGS! I gotta stop now, I'm getting all giddy!
Todd