when to play A2, etc.

[CORed]

The straight value of A2-A5 is very limited. There is only one combination of ranks for each hand that will make a straight using both pocket cards. Connectors JT-54 have four combinations of ranks that will make a straight using both pocket cards. If you flop 4 to your straight, you will always have a gutshot draw, with 4 outs to a straight that may be second best and 3 outs to a top pair that will often be second best. If you make a wheel, there is always a better straight possible. With A2, there are 2 better straights possible. A2-A5 offsuit should generally only be played in blind-stealing or blind-defending situations, or as a free or cheap play in unraised blinds.