I would say that you could get rid of the bottle and pacifier completely at this point, if you are ready to do that. I think it will be easier for your daughter that way, at least. I had both of my kids off the bottle at a year and it was no problem at all (I think they adjust more easily when they are younger). Your son will probably deal with it in his usual manner when he does not get his way. But again, I think sooner may be better.
That said, I will tell you that the pacifier was a different story in our house. My older son loved the pacifier but the younger one never really cared for it (he began to suck on a blanket instead). I let my older son keep the pacifier until almost 3-1/2. He was so in love with it (and he only had it at bedtime) that I couldn't bear to take it away from him. The dentist told us he needed to be rid of it by 4 if we wanted to avoid possible permanent damage to his teeth, so we made the plans, and when we got rid of it, it was not a huge problem. That was last summer; his teeth are completely back to normal and perfect now, and he doesn't even remember the pacifier anymore. I'm just sharing this because I know how it is to let your kid have a comfort item, maybe a little bit past the "expiration date." I don't regret letting my son have the pacifier for that long. He loved it for the time he had it, and when it was time to go, it was not easy for him, but he moved on and recovered very quickly. I think that you, as the Mom, will know the best course for your kids.
As for mimicking the younger sibling, my older son did this too, but it was with different things, and I just thought it was terribly cute. When the baby was tiny and would lay on blanket on the floor, his big brother would want lay on the blanket too. When the baby started to crawl, his big brother went back to crawling. When the baby began to say words in his own special way, his big brother would talk exactly the same way (and announce that he was talking his little brother's language). If you decide to do away with the bottle and the pacifier now, my guess is that your son will start to mimick his little sister in other ways. I think that is just what kids do. They learn by mimicking us, why not mimick a younger sibling? Eventually, I think the desire to grow up overtakes them and they will no longer emulate anyone younger than them, but I'm no expert. Just my thoughts. :)
Best of luck to you! :)