I've played 20-30 games of SC2 Mafia so far, and one thing that stood out to me was how frequently I needed to input text commands. While text commands aren't necessarily a bad thing, they do create two challenges for players. First, they make things more difficult for new players, who may not even be aware that there are text commands. Second, they can eat up time for players who need to take actions quickly and for which a difference of only a few seconds can be significant.
As an example of the second issue, I often find myself in roles such as doctor or investigator which frequently need to update their last wills as a record of their activities. While the time it takes to click in the chat box and type "-lw" may seem insignificant, the 2-3 seconds it takes to do this really are noticeable, especially in the night phase when I also need to decide who to protect/investigate. Having a button to open the last will, perhaps placed over the chat box near where the last will box pops up, would be extremely helpful. If it were labeled "last will" this would help out new players as well.
On a similar note, typing in "-jail #" as a jailor might take only a moment, but that time can have an impact if you become suspicious of someone right as the day ends and may not be able to type it in fast enough. Adding a button system to do this such as the one that other roles have for their actions would improve user-friendliness.
-JPlayah