The explosion-on-death feature of Blaster drone was converted into the Blaster augment, which was possible to get for Wasp from a recent event. You can check if players have this augment equipped if you press Tab.

Voting does work. I used it before and a moderators sometimes do come. The problem is, for a vote to be registered and sent to moderators for review, multiple people (something like 25% of the team) need to vote for the same player. So it's possible that you are the only one trying to vote for some players, and your reports aren't going through. It's also possible that the reports ARE going through, but there are simply not enough battle moderators online to respond in time. The difference between this and chat reports is that reporting of chat violations is automatic and doesn't have to be done in real time. If a player is hacking or sabotaging, other players need to vote for them, and a battle moderator needs to come to that battle before it ends, and witness the violation with their own eyes. Whereas with chat, if a player is swearing or insulting, an automated system detects it and saves a log of the conversation, which chat moderators can then review later, even long after the battle ends. Chat moderation is also handled by a different, larger team, so there are often more chat mods available to process chat (but not battle) reports.

No, you don't get the reward. Your team has to pass the current stage in order for you to claim the prizes. So for example, if you bought the "start" bundle and your team gets eliminated in the current stage, you get nothing (apart from the 6 paints) unless you buy a "pit stop" bundle.

Good question. According to the announcement you indeed have just two days to earn stars. From what I understood, the stars can only be earned during the "main race" time, while day of the elimination race is between the two bottom teams only, and the remaining teams' stars do not contribute to the event in any way, individually or team-wise. Pretty sure that even if you're in the team that's participating in the elimination race, the stars you earn during the elimination race do not count towards your individual total for that stage, so if you earned 156 stars in the first two days and 67 stars in the elimination day (and your team won the elimination race), you still only get rewards for the 150 stars. If you change to a winning faction, your stars for each previous race day are counted. For example, say you're earning 100 stars every single day and your initial team gets eliminated first. If you don't change faction, you get absolutely nothing (besides the paints). You can keep earning stars in the next few days, despite being part of an eliminated team. Then, if you switch to a winning team in the end, you will get rewards for all of the previous tiers. Like, there's no situation where you would get rewards for stage 1 and stage 5, but not for stage 2, 3 and 4. Keep in mind that the above is just my personal understanding — you should check official info to verify. Hopefully the next v-log will clear some things up.