it's possible she's still not sleeping enough. what's prompted the napping on the couch? my two year old sleeps a good 11-12 hours at night and still needs at least a good two hour nap every day. she's a horrible monster if she doesn't get that nap fairly consistently!
does she have her two year molars in? if she's cutting those teeth, make sure she gets ibuprofen or teething tablets (i recommend both) at sleep times so she can be comfortable and sleep longer.
dad being gone a lot and having a new baby can definitely prompt those scary tantrums! my husband is deployed right now and i'm pregnant, and my two year old has really become clingy and wants to be with me ALL the time! and she is a screamer too.... if she doesn't get what she wants, she freaks out! she's always been this way, but it's gotten way worse over the last couple of weeks!!! i just discovered last night that her two back molars have finally broken through, so i think that's what's been making her behavior so much worse lately.
i think that pulmicort is what turned my oldest child into a little heathen monster (she's usually just the sweetest child you'd ever meet!) and it took her a good solid month to become sweet again. but if your child's behavior just started last week, it's not likely due to the pulmicort. but watch for negative changes in her behavior when you use those medications just in case there could be a correlation.
and for the dietary question.... something i discovered in my oldest, is that any foods with artificial colors like the reds, blues and yellows, and things with high fructose corn syrup really set her over the edge! she is like jekyl and hyde! sweet as can be on an all natural diet, but the second i let her have something with those ingredients in it, she's a completely different child! very emotional, very short tempered, very MEAN! so i have to really watch labels with her. even things like some juices, and fruit snacks, and children's vitamins, and most medications (i can only give her dye free) are horrible to give her!
when my two year old starts with her tantrums now, i don't show any emotion at all. i just pick her up, and dump her into her room and shut the door. as i'm closing the door i tell her she can come out whenever she is done. she usually screams a few minutes and then comes out with a tearful apology (it's really quite pitiful!). occasionally she's been known to stay in there for nearly an hour, but i will NOT go get her!!! she has to learn to control herself and so i let her make the choice to come out when she is ready.
anyway, these are all the ideas i had when i first read your post. hope something here can help! :)