Re: Do I need a guy and a sheet on each side of spinnaker?
We sailed by spinnaker alone when figuring out the asymmetrical. This was on Lake Union on light wind days, so we weren't in a position where blanketting the spinnaker with the main was likely to be necessary (that is normally a useful safety maneuver).
The nice thing about sailing with spinnaker alone is that you can easily see the whole thing from the cockpit and thus more easily experiment with sail trim and handling. You can also reef the main to get a similar effect.
I recommend having two crew and an autopilot or three crew for figuring it out. There is a lot going on, even more so with a symmetrical spinnaker and pole (I have little experience with those) compared to the asymmetrical cruising spinnaker that I use.
It's not that much help for flying your symmetrical spinnaker, but I'd be happy to show you how the asymmetrical works on my boat since we're both in Seattle.
Did your KR24 come with the spinnaker and pole, or did you buy them afterwords?
boats that I sail on regularly: Pearson 28-2, Rondar 505, Yankee 30, Blanchard Junior