Relax! You will pick up what you need on the fly. Just have some support available (LCs and a few friends who have EBF'ed are the best support you can have!). It's also important to remember that BFing makes you hormonal and you'll think you're doing it wrong at LEAST some of the time. BUT, you'll probably be fine, and you've got your support system for if you really do need help.
1. For those who did EBF, how many bras and nursing tanks did you have?
I have like 10 now (I'm a 38DD). However, I only got three sleep nursing bras for the first 4 weeks (when I was sleeping all around the clock and didn't really get out much). I got these ones:
http://www.amazon.com/Medela-Womens-Sleep-Nursing-Bra/dp/B000JIH8WQ. They were also nice for putting pads into. Get them just a little on the big side (I got L and XL and I appreciated the roominess of XL).
2. Did you have different bras for night time and for during the day?
Again, not at first. Now, I only wear regular nursing bras during the day (I love Nummies). I wear nothing at night (we cosleep so DD can have access with minimal waking up from me!).
3. For the moms with a larger chest (pre-pregnant in the 36E range), how much bigger did you get? Thus far I have been able to stick with most of the bras I was using before getting pregnant but they aren’t breastfeeding ones so I will get new ones.
Just get a few sleep bras now and get fitted after you give birth and AFTER any engorgement subsides. You don't want to end up with the wrong size.
4. What brands work best for that size and will I have to order them online?
I love Medela and Nummies. You can get LOADS of great bras (and a free fitting) at the Breastfeeding Center on K St. I highly recommend it. They also have free classes for new moms (you can take them when you're pregnant so you know what to expect, though).
5. Did you buy breastfeeding bras before the baby was born/do you recommend I have a couple to start with and then add to them?
Yes, and they don't fit! So, no, don't buy anything but a few sleep bras.
6. Any advice on what to expect when transitioning from EBF to a combo of pumping and breast feeding?
Join a group and take free classes. VHC and K St have free support groups (VHC's is Weds and K St's is Tues) and those are GREAT places to learn more details. The free pumping class at K St is also great (but fills up quickly). In general, don't worry about pumping until you're about 4 weeks in and you're starting to get the hang of things. You have plenty of time to get used to it and build a freezer stash. I started pumping at about 6 weeks (once per day) and built up 200 oz for my stash.
7. Anything important I am not asking that I should know?
You literally never know if you or the baby will have issues, but know that breastfeeding is HARD the first time you do it. It is still SO WORTHWHILE and you will eventually just love it so much, but there are lots of challenges.
1. It will (probably) hurt. Those books that say it only hurts if you're doing it wrong are LYING!

It will probably hurt for 2-6 weeks. I hurt like hell for 2 weeks, and it was a little uncomfortable for 2 more weeks. Now, at 9 months, all I feel is the happy hormones from nursing. It takes a while for your nipples to adjust, and for the baby to get good at latching (even if they latch well). Triple nipple ointment is your friend if you get damaged nipples (get it from a compounding pharmacy like Prestons).
2. LCs are a godsend. Call one whenever, wherever. They are worth every penny. If you can't afford to pay for a consult, the groups at VHC and K St are run by LCs who can answer your questions.
3. You WILL think your diet is making your baby have reflux/gas at about 6-12 weeks. They are just fussy and gassy at that stage. Literally like 90% of the moms I know thought their kids had reflux or went on elimination diets. It's just a phase.
4. Kellymom is a great resource:
http://kellymom.com
5. You will be fine! Breastfeeding is pretty hard but ends up being pretty cool. Best of luck to you and congrats!