The One X is a similar unibody style - but people found that basically a guitar pick and suction cup could pry the edges of the screen out of the plastic shell. I would only do it if it is really easy though as it isn't a hardship to plug it in.
HTC second gen didnt have memory cards, this gen wont either, its much slower at reading so they scrapped it.
What is that based on? I'm not sure what second generation means for HTC since they pump out so many phones. Until someone cracks this open, I wouldn't jump to that conclusion yet. In my eyes, it is much easier to make a phone with a microSD slot (UHS-1 speed is 104mb/s) and have a 8GB and 16GB model as they do. The phone is the exact same except for the bump in memory and they charge $100 more for a card that is $12.
The titan and radar have built in memory. Was discovered with a teardown. The system design is similar to all htcs android internals which use internal memory. The memory cards were recycled win mobile and android handsets