Design invites (working on this now) Send invites (when should I send? When should I ask for rsvps?)
We will send ours 3 months ahead and set the RSVP date 6 weeks prior to our wedding. We are keeping 2 weeks on purpose to received the late RSVP and track any missing. Our personal limit is 1 month before the event (if you still haven’t RSVP’d we consider you’ve declined).
Dress alterations (I already have my dress – definitely need it hemmed, maybe taken in a bit)
I would at least take an appointment now (maybe for April). Wedding season starts in spring, you want to make sure you have found a seamstress.
Engagement shoot with photographer
Any time you want, but if you want to have the pictures ready for the invites, you should contact your photographer ASAP.
Book hair/makeup for day of, and do hair/makeup trials
Again, same than for the seamstress. Better take appointments ahead, to make sure you have the MUA you want.
Finalize centerpieces, etc with florist
I would wait a few weeks before the wedding, assuming you’ve already discussed specifics with the florist. You’ll also need to know how many tables you have for the centerpieces.
Welcome bags for out-of-town guests, Wedding favors
It’s not a huge priority in the sense that the attention is nice, but if ever for any reason you couldn’t have them, it wouldn’t be the end of the world. I would care about that whenever you have spare time.
Seating chart, Escort cards / table numbers
After you’ve received the RSVPs. You can think of the design you want and all, but don’t plan your tables just yet.
Finalize ceremony with Rabbi, Order Ketubah
I’m not familiar with the Jewish tradition, I would call the Rabbi directly to ask him.
So basically, I would focus this week on making appointments for later. Get this off your head and in your calendar. Then you can focus on something else in your planning (ex.: e-pics, invites).