Going for the Trifecta

Now that I have de-emphasized marathon training, my focus will be hitting my lifetime goals in the 5K,10K and half marathon. I figure that I have about 5 years of potential improvement to do so. I posed the following question on RWOL last year:
Which of these is most difficult to achieve?
19:00 5K
40:00 10K
1:30:00 Half
The consensus was that the 1:30 was easiest followed by the 40:00 while the 19:00 was generally considered the most difficult. The answer to that question depends on your strengths and weaknesses. The sub-19 may very well be the easiest task for me because I have not lost much raw sprint speed since high school. I'll bet that I could beat a lot of sub-3 marathoners in a quarter mile sprint.
This month will provide an opportunity to assess how close I am in both the 5K and 10K since both races are competitive and run on flat courses. As for the half, my online buddies in the Sub-1:30 goal group suggested that I am currently capable of it right now given the perfect circumstances. I like the encouragement and believe that I "might could" eke out a sub-1:31 but just don't think I am quite ready to break the big barrier yet. Maybe by the end of May, I'll have a shot in Idaho.
Let me define what I mean by perfect circumstances:
First, the weather must cooperate. Ideally, I'd like to see between 45-65 degrees with no wind, rain or humidity. In a 5K, I'd rather it be 65 than 45 and in a half, cooler conditions are preferable.
Second, the course must be fast. There may be some small rollers but they must be short, followed by a downhill and relatively early in the race. Of course, flatter = faster but outside of a track, truly pancake flat courses are hard to come by, especially locally.
Third, I must have close competition. In a small race, there is a high probability of ending up in "no mans land" in which no other competitor is within reach, either ahead or behind for much of the race. Pushing the pace is more difficult when running alone.
I've considered my current PRs at all 3 distances and there was no case in which all 3 conditions were met.
5K- 19:27- 75-80 degree weather and course included a gradual rise from Mile 2.5 to 3.0
10K- 41:14- solo time trial.
Half: 1:32:49- significant hills in the last 5 miles.
I almost forgot to mention that in addition to all 3 conditions being met, I will need to have my "A" stuff to do it.
I welcome any comments and points of agreement/disagreement.