[greymule]

Maybe it would be more simple to base the runner closest to home on where they were at TOP?

For intentional INT on fly balls, that would work. In fact, it would make a good general rule (for INT on fly balls). No runner should be able to advance or score simply because he reached the next base or touched the plate before another runner committed INT on a fly ball. (INT before the BR reaches 1B would probably cover most of this, but there still might be a loophole.)

I would also change the ruling on this play:

Bases loaded, 1 out. Slow runner B4 grounds to F6, who throws to F4 for the out on R3 as speedy R1 scores. F4's throw to 1B is in plenty of time to get B4 and end the inning, but R3 (who is already out) deliberately interferes with the throw. The ruling is that R2 (the runner closest to home) is the third out, and since R3 had been put out, the out on R2 is not a force, and thus R1's run counts.

On such intentional INT, I would give the defense the advantageous third out they were trying to get at 1B.

There are a half dozen ASA rules I'm not particularly fond of, but they don't have the potential for disaster, like letting a team benefit from committing deliberate INT.