1) Is stopping and picking a snail up and carry it safely across the the gravel path to the other side to prevent it from getting smashed by other people, a skillful, neutral or unskillful act, and why?
I think it is sweet of you! Compassionate. But I often observed that they tend to turn around anyways if the path gets too unpleasant for them, their judgement may not be as poor as we think.
2) Is this skillful because we know that the snail will be smashed and we can prevent this from happening by carrying it across?
You don't know for sure, do you? But if it's very likely to happen, since lots of folks trot by, why not, if it makes you feel better.
3) Is it unskillful because we ...interrupt ... events unfolding... that is not our business (even if we would like to make it our business) ?
Well, if you pick it up, you must
be part of the 'events unfolding', and the snail is reaping some good karma, to meet you!
4) If this is skillful, does that mean that ideally we should stop and help EVERY snail across? How do I know where to draw the line? (I guess I should think of "the middle way" here and that helping a few is better than none)
Well, if you miss school, the bus, work, basically damage your own life, to help a less evolved being, then it's probably not so skillful, but if there is nothing better to do...? (Are you sure...?)
5) What are your other thoughts if any on this?
Saving a sentient being out of a danger that it is not aware of is skillful.
If you don't lose other things that may be in your life out of perspective and things stay in proportion, -nice.
Like, -don't get tunnel vision on snails, as they are not an endangered species.
Perhaps your caring nature will be most happy in environmental issues on a larger scale as well, such as creating places in your garden, if you have one, where butterflies find food, on certain plants, etc, and of you meet a little snail, help it across the street as well.
I save snails too...pick them up from the walkway...
I don't want too many in my garden, and so I "help them out". Into a near meadow.
I can't kill any...