It's been a few years, but I've been in Myrtle Beach during bike week several times, but never on my bike. I'm sure something like bike week can be whatever you want it to be, but (as an observer) here's what I see when I've been there:

The roads in and around Myrtle Beach are pretty crowded that week, and riding in the area would be limited to "parade speed" most of the time. It's probably better that way because a lot of the people who come seem to be more interested in being seen than riding. The vendor areas are pretty cool to walk through. I've taken my kids there and we've never had trouble from anyone. There's a lot of bikes parked outside bars all day long, which means you's need to be a little extra vigilant on the road. Honestly, I think it'd probably be fun if you just think of it as a big party instead of a motorcycle ride. But the lighthouse tour Mike mentioned would be a whole lot more fun (IMO).

Also, I don't know if this is still an issue, but the city of Myrtle Beach passed some ordinances a few years ago to discourage motorcycles in the city limits during bike week (pipe noise limits, helmet law, public gathering restrictions, public drinking restrictions, etc.). At the time, everything just moved to North Myrtle Beach and other surrounding towns. Like I said, I don't know if that's still an issue this year.

Have fun if you go!

Will