Never too early to start thinking about details, it will give you time to process your decisions and maybe make changes before they are put in the house and it's too late to make changes. I have been thinking details like that since before we broke ground. I have made many changes just by imagining how they will work in the house. Study the plan thoroughly. When I did, I realized the master bathroom door would block the master linen closet, so I changed the master bath door to a pocket door. I changed windows surrounding the fireplace several times, before they were ordered. Things like that, you don't want to wait til the electrician asks you where you want plugins to decide that, and then in a rush miss some places where you, after the fact, would have really liked to have one.

You need to think of these things, however understand that a room dimensions are not precise.... I would not be measuring kitchen cabinets until drywall is in.

If you're crazy, so is everyone else here. Seriously, planning ahead is how you end up with a house that'll work to fit your needs.

perfectly normal

Yes. I know what you mean. That's where my mind lives...

The trick to thinking and planning for the design and construction of a new house is to understand the sequence of phases and steps that normally occur during design, bidding, construction and occupancy. Think about drawer pulls when the schematic design is still in flux puts the cart before the horse...the most important thing about forming and pouring the foundation is to ensure that all exterior dimensions are correct, since once the slab is poured that will be the dimensions and shape of the subsequent framing. Step at a time...:-)

You're not too crazy, not for this neighborhood, anyway. Virgil makes an excellent point about understanding sequences. I thought I understood them in the abstract, but was still sometimes unprepared for some "details" that had to be decided before rough-in. Sure you can move a window or a door later, but did you want a receptacle there or a light with a dimmer? That could affect a change to a pocket door. Did you want to recharge your hand vacuum in a closet? Make sure you have a place to plug it in. Precisely what lighting will you use in your vanity? That will determine where those boxes go. We still ended up with one light switch that's too low, but at least that wasn't my fault!

It's never too early to think about where electrical outlets go, in particular.

Code will dictate some outlet locations. When we enclosed our carport, we ended up with plugs on two 20" walls. Who knew they'd be perfect for the electric pencil sharpener and cell phone chargers? Special outlets, yes. Think about where you want your bedroom lamps and switches, where you want some 3-ways, where you want to control your kitchen lighting, etc. And pick out your lighting. We've remodeled rentals and I've gotten a call from the electrician at 7 pm: I'm ready to put your fixtures in tomorrow; please have them on site!

Also, think about your kitchen layout now. They have pullouts for garbage/recycling. "Work" your plan in your head. Prep some meals. Clean up. You want to be prepared for when it's time to order your kitchen.

You can measure for cabinets before the drywall goes up. All you need to know is how thick the drywall will be, which is normally 1/2 inch and add that to your measurements. My KD said she could measure as soon as the studs in the kitchen where up and she did.