I don't think you have a leg to stand on.
It is modular - the modules are taking time to come out, but it's still only a couple of months after the platform went on sale and demand has meant they have no spare capacity.
I'm not sure I've ever seen promises about range, because everyone accepts it's highly variable depending on conditions.
You're making a lot of assumptions about what they're going to do with the 3 antenna ST-16 - has anyone spoken to an official representative to find out the upgrade path?
The camera is challenging, but again we don't actually know what Yuneec's position on this is, so legal threats aren't going to get you far.
For 'bad' Typhoons, including crashes, they seem to be very happy to repair and replace as appropriate - that's a lot better than others in the industry.
The new firmware seems to be an overall improvement, but as with any firmware upgrade, caveat emptor and all that - get the dealer to do it and only if you're certain you need the benefits.
For all of your issues, there are people getting some great flights and footage out of the H, and it seems that Yuneec are working on improving the platform, even if a lot of stuff is happening behind closed doors.
You're making a lot of assumptions that they're selling in bad faith, and pulling them into a lawsuit is not going to actually help anyone - it won't get you a better drone, it won't make Yuneec more communicative and it will make everyone (apart from lawyers) poorer.
You would do better to actually talk to a senior Yuneec representative (not a dealer or sales guy) and find out what their plans are. Yuneec themselves need to learn how to communicate better with their customers, but that's not a basis for a lawsuit, it's just poor business.