The online voting is, I can imagine, something that will eventually come. I made note of the computer glitches we had when we used modern technology in the last election. We didn't have the results until the next day on some of these. What was supposed to be an advancement turned out to be a real concern, because people were concerned that there was a rigging or that there was a problem with the machinery. Again, security's always an issue when you talk about online.
As to mandatory voting, people have rights and freedoms to choose to vote or not to vote. That's why, again, if we force them to vote, it starts moving into being heavy-handed and takes away that freedom of choice that we all find so important.