Thankfully, most mind mapping tools are built to eliminate this overhead. There seems to be a clear keyboard-based convention for creating mind map. Hit the [INSERT] button for a new child item; hit [ENTER] for a new sibling; navigate with the arrow keys. On my last project (a web mapping application) I opted to design and plan the entire thing with MindMeister. MindMeister is an amazing mind mapping tool, with a powerful collaborative twist. By the time my project entered the development phase, our work plan consisted of about 1,000 action-items - nearly all of them estimated in hours, and none longer than two days. By the time development was done, the detailed work plan of this year-long project had about 14,000 revisions and 1,700 items. That's a big mind-map. When fully expanded, this tree would require you to scroll the screen 20 times in order to see all of it.
The fact that there were so many revisions illustrates how much of the initial plan had to change as the project progressed. That's another thing that's so great about mind maps - editing is so easy. You can turn an entire plan on its head in seconds with a few drag-n-drops. You can delete and throw away the parts that didn't make much sense. You can re-prioritize at will.
The simple ability to visually rearrange your plan on screen quickly is crucial. Plans that are harder to change often remain unchanged and thus ignored. Ultimately, this makes people not want to plan at all. Why bother, right? If 40% of the plan is going to change after only four weeks then just plan ahead for those four weeks and plan a bit more when you get there. If only that were true. The sad truth is that there is immense value to planning ahead as far as you can think, but people hesitate to do so. The price of redoing your serialized plans is simply too high with existing planning tools. Many people miss out on the value of planning ahead because the process is painful, slow and time-consuming.
In fact, I propose that most work plans nowadays end somewhere I call the "screen horizon". Most people have no problem writing plans that fit into one screen, because that's the limit to ultimate quick editing. You can drag, drop, cut and paste very quickly as long as you don't have to scroll your screen too much. But no serious amount of planning can really fit into one screen. This is a real limitation, if you think about it. Your crappy planning tools dictate how far you allow yourself to think into the future. With a better tool you should be able to push that screen horizon forward and plan comfortably until you decide you've planned enough. With a better tool, you wouldn't mind planning further ahead, knowing very well that your plans are bound to change as your project advances. Changing plans is fine, as long as editing your long-term plan is as easy as dragging around items on a single screen.