I'm a 29er rider, and a full sus one at that. I have done DH on mine and ride Danbury quite often but if you want to get into free ride and DH you need a different rig.
29ers just don't have the wheel strength and on tight DH tracks you can't turn them as tightly in the same space.

As Danbury is quite smooth, as suggested, HT jump bikes are a good choice, there are no rough rocks to use your full suspension travel on.

I have a FR/DH bike and it gets used for evrything, my preference is for more Dh orientated stuff. As mentioned there are no rules, but clearly some bikes are better suited to certain terrains, this is why some end up with multiple bikes, get into riding and you may decide to change bikes or buy another.

29"ers are clearly most suited to flatish XC type routes but can be ridden anywhere.

Decent frames shouldnt be snapping if you land correctly , watch BMXers and dirt jumpers land huge jumps/drops on hard tails.

Id recommned not rushing into learning to jump, Im not a great expert at it despite riding for quite a few years, Danbury is good in that you can just do the runs at a slow speed, everything is rollable but as you get faster, youll find yourself getting air out of the various bombholes, etc

I cant agree with Matt more, people are all too eager to try and fly off big jumps too soon, youll only injure yourself, just learn all the other techniques first, tips from friends or training can be done via Tom Dowie at Chicksnads, Uk Bike Skills or various free courses through Hadleigh MTB club at the Olympic track, everyone I know has learnt loads of real basic skills even if they have been riding for years.

Jumping and rideing skills are two different things, better to learn the correct bike handling skills (corning, pumping, steep decents, off camber, roots ect) before trying to go big in the air