I am also semi easy going... Can an A type person be that way?
I have also collided in MK with a fellow runner who saw a second tier character on course left. The issue.... she was course right and made an immediate left hand turn without looking. All I saw was a flash coming across and it was kind of like NASCAR. I was PO'd at the fact that she nearly ruined my goofy at mile 5.5 of the weekend. Fortunately, no one was injured in the wreck.
For the most part, folks are well behaved at WDW marathon. I have seen a few cases where folks get tangled, where a runner did not see a speed bump, or where a spectator walked along the edge of the course. These are normal for a race with 50k runners over the weekend. Though it does bring up a great time to think about etiquette.
We should all be respectful of the 2-3 feet in front of a fellow runner and aware of the 2-3 feet behind you as a runner. (I use runner, but mean runner, walker, run/walker, jogger)
If running in a group, run NO MORE than two abreast, please. There are places on course where you can go wider, but even there, you are possibly forcing a faster runner to go very wide.
If you find yourself in a spot where you are going really slow compared with others (e.g. you are in a really fast corral or you are just starting a walk break) hang near the side of the course. Right or left dos not matter. But, please keep a 1 - 1.5 person width between you and the edge of the pavement. There is a fast moving train of folks who run just on or just off course. Moving to the very edge bottles up this narrow path.
When slowing for a walk break, move to the near edge before slowing. Raise a hand, look around and otherwise make sure you do not have a tailgater. Too often folks will just slow up without looking around or slow up then head sharply to the side.
Keep your line. Predictability goes along way. You will find especially near the start that you have hundreds of extreme zig zaggers. They cut gaps and create havoc. Stay on your line as best you can. You will conserve energy and possibly avoid getting tangled.
Announce yourself a simple coming through, coming left when approaching a group or a wobbly runner will let them know you are about to be next to them. I find that rolling roadblocks (groups of friends who do not keep it to two abreast) will often open a hole with these simple announcements. Obviously, a thank you as you pass is in order, as well.
Aid stations can be a mess. All aid stations should be set up the same way. Usually water then sport drink. There is always one station that did not get that memo, but all 20 other are usually that way. First, if you are passing a station, move to the center line as you approach the station and just run through. If you are looking for water or sport drink or both, do not hug the edge of the road but look at the traffic of the station. You will see the volunteers are about 2-3 feet out from the table. Then you will see a line of walkers just inside the volunteers. Just inside these guys are the runners who are looking for a handup without stopping. Be careful as you slow or stop running. You may have a tail gater who is thinking you are looking for a hand up. Make eye contact with the volunteer and they will work to get you the cup. If another runner grabs yours keep moving. There are other volunteers. Most of us are in the thicker part of the race (i.e. most runners). Understand that the first set of tables is the most worked and under stocked table. Look to beginning you search for a volunteer near the middle of the row of tables. It will be much less crowded.
When finished with your cup, take care throwing it away. Look to make sure you are not getting passed as you throw the cup off course. While refreshing, most runners really do not like the sticky residue PowerAde leaves. Also, it is not a game to splash the trash raker. Try to throw at the trash can but take care to not throw at a person. (seems obvious now but watch) I tend to carry a cup a little longer and am often past the last trash. If you find you are in this spot, throw next to an existing cup. You will see that many others in front of you have done the same.
When fueling, throw your refuse to the side also. The place on course where bananas are passed up looks like a bad cartoon with all the peels in the roadway. Most fuels are slick and sticky.
Back near the start… It will feel chilly pre-race (hopefully). Many runners will use trash sacks or other throw down clothing to keep warm before the start. If you are removing clothing in the corral, please make sure your discards are on the outside of the fence. They are not a tripping hazard to you, but can be to others behind you.
Just be aware that prerace and early race potty breaks are equal opportunity or coed. To many it is disgusting and on a normal day I would agree. Just make sure where you are if you head off course for a break.
Thank a volunteer. No matter what race you are running in, the race would fail without these folks. A simple thanks for being here goes a long way.
I know there are many others, I just hit a block here.