Artoomis said:
Why not allow an extra 5'-step?
Actually, having an extra 5' step per round is the least of the problems presented here and does not address the true multi-action Haste issues. It's almost irrelevent to the conversation (except with regard to whether it can or cannot be done).
Example 1:
I use a partial action and a 5' step to back up and cast a spell.
I use a standard action and a 30' step to back up and cast a second spell.
As per this example, you are not taking a second 5' adjustment step (since you are not doing a full round action). So, the extra 5' step does not come into play here.
Here, the larger issue is whether the 5' step results in an AoO due to the 30' movement in the standard action.
Example 2:
I use a partial action and partial charge 30' forward and attack.
I use a standard action and a 5' step to back up and cast a spell.
As per this example, again you are not taking a second 5' adjustment step. So again, the extra 5' step does not come into play here.
Here, the larger issue is whether the character can change his direction after charging.
There are a lot of "you can only do this once per round" type of rules that cause problems and conflict in resolution when you bring Haste into the equation.
The resulting questions from these rules are hard to answer if you do not segregate out each individual action.
It is just a side effect of segregating out each individual action that a second 5' step would be allowed and would conflict with the FAQ.
So, the easiest solution to solve all 3 problems (Example 1, Example 2, and the original example of move back and drink potion, move forward and full round attack) is to segregate out each individual action and change these types of rules from once per round to once per action (e.g. one 5' step per round to one 5' step per action, or must charge in the same direction for the entire action as opposed to the entire round).
As a side note, the reason one 5' step per action might still be a viable rule is for things like Shot on the Run where a character could move 5' and fire (normally not provoking an AoO), and then move 5' back. The one 5' step per action rule would then enforce an AoO. Of course, this still gets into the retroactive question, but there is no way around it for any ability (Hasted or Shot on the Run) which allows movement, action, and movement within a round unless you consider the latter movement to not affect AoO rules on the earlier movement. It's obvious that the designers did not take these types of things into account. But, that is understandable since it is difficult to anticipate any scenario with these types of unusual conditions (i.e. move, action, move).