At our local ramp we joke it is the cheapest entertainment in town. Forgetting to put in the plug, remove straps, tow vehicle launching itself, ramming the dock, 2wd pickup spinning it's tire, unable to pull the boat out of the water..... A lot of people obviously are newbies so I and my friends are quick to offer a hand...in the long run it speeds up the process for everyone. Another observation, the smallest boat always has the most passengers
You didn't mention whether you have a bunk or roller trailer.... Bunk trailers usually have to be rolled in a bit deeper to float the boat off but in either case, once the boat starts to float you don't have too much more than the trailer to deal with. Sounds to me like you've given everything careful thought and I suspect things will go smoothly for you. Preparation is the key to efficient launching and recovery. I don't think I'd want to try by myself if I didn't have to. Launching wouldn't be too bad but recovery would present more challenges.
+1 on the entertainment value.
Thankfully that didn't happen very often...