Hi E.,
I have one of these! ( A 3.5 year old.) Questions, in order:
1. 7 o'clock bedtime. Yep, believe it or not, it's actually better for kiddos to go to bed when they are tired. There's even a great book called "The Seven O'Clock Bedtime" that I would pay good money to have all of my preschool families read, because kids at this age do need between 10-12 hours of sleep. We have a seven o'clock bedtime at our house and I love it. It allows my husband and I to get in some face time before bed. Yes, your stepson may wake early, and I hate to say it bluntly, but this is what parenting is about. Children are not convenient sleepers, mine included!:) But if he's tired and pleading with you to go to sleep, please respect this.
2. Just my opinion, but if he's this old, he should be out of a crib. You can do a futon on the floor, so if he rolls off, it's not a big drop, or a mattress on the floor too. IMO, toddler beds are a waste of money.
3. Go with your instinct on the booster. Unless he's exceeded the height/weight limits of his carseat, you are making the safer choice in keeping him in it. Good call there.
4.In regard to the stuffed animal: this is likely his security object, and you should really honor this. He's got two households to wrap his little head around, (possibly daycare or preschool, too?) and a new parent (you). This isn't to make you feel bad or guilty, but that is a lot for a child of any age. Children carry around their attachment objects because, frankly, they need to. I would strongly encourage you not to make this the battle you pick, but rather to provide as much warm, loving and consistent care as you can. My brother had a Cookie Monster doll when he was little that went everywhere with us until he was nearly seven. This was important as his folks (my mom and stepfather) divorced when he was around 5 or so, and boy, he clung to that thing. If you consider it like this, the security object is the One Consistent Thing in your stepson's life. It's a constant. Let him keep it until he's ready to let it go. It might not be seemly to you, but you aren't 3.5. It will be a loving, gracious thing to do and ten years down the road, you will be glad you respected his need for this object, instead of hurting his heart by making limits/taking it away.
If you want a couple book titles to start with too (because parenting is HARD!) I'd go with "The Science of Parenting" by Margot Sunderland (who has more to say about age-appropriate responses to children and gives us insight on the child's social/emotional and brain development-- it's actually very easy to read) and "How to talk so Kids Will Listen and How to Listen So Kids will Talk" by Faber and Mazlish. I've worked with kids for nearly 20 years and this is by far a favorite. Lastly, any of the Positive Discipline books can really help, too. But for now, let Daddy do the disciplining whenever possible.
Best wishes on this new venture in your life.