I went for 2,3, and 4.
Right now, they are going to go for a big bite. I don't believe confiscation, but they might try for "turn them in". Even if no one turns them in, it's still a law, and then you can get popped for it anytime (see Atlas Shrugged). EBR bans, mag bans, absolutely on the table. I just read that the gun control groups are pushing Biden to push all the credit card companies to refuse any gun related business. Given what we just saw with Parler, and also that a ton of institutions are now publicly stating they will no longer contribute to Republicans (for fear of reprisal), I see this as more of a possibility than the past efforts on it.
I'm hoping the fail at the big stuff, but if they do, they will of course go to incrementalism. In fact that might work better for the given the current climate and history. The last big efforts flipped congress. It could happen again. If they keep things small and spread out, the way things are going right now there won't be a house flip in 2022. They seem to have enough support for "common sense" control. As long as they don't take the handguns and shotguns away from all the libs that bought them in the last year, they'll get stuff like standard capacity mag bans easy.