that looks like a fun ride. and TnT is a great program i'm sure they could help you prepare for it.
#1 - depends. you'd probably be more comfortable on a hybrid than some aggressive racing bike. but fit is probably more important than the bike itself. i do agree about the ability to change hand positions on a road bike being a huge plus, even if you spend most of the time on the hoods. for me a road bike is the way to go but your mileage may vary.
#2 - i bought a bike at go ride. they often have good deals on closeout but you'd probably want to know what your looking for before hand. i've heard both good and bad reviews about them. mine was indifferent although i'm glad i didn't need to rely on them to do a fitting. check out a few shops and do some tests rides on different brands/models to see what's best for you.
#3 - actc had a nice profile viewer which is great for comparing climbs: http://www.actc.org/profiles/index.php
i don't think there are any huge hills on this ride but being comfortable climbing always helps. it looks like mostly smaller climbs and rollers so it's probably more important to just get some longer rides in.
as far as stops, frequent is fine. you may want to avoid really long stops since it's harder to get back into the rhythm but you'll work that out as you put some mileage in.