I also wish the things you could apply Stasis and Magnesis on were a bit more consistent (I am looking at you, chests in hard to reach places).
Magnesis only applies to metal things, and chests can be made of several different materials - wood, stone and metal being the most common. The ones in Shrines are probably the only ones that aren't easy to tell apart at a glance, since the metal and non-metal designs are fairly similar.
Stasis can be applied to almost anything that moves that isn't a living creature. I haven't really noticed any inconsistencies with it.
Also, played and now finished DLC2. I'll keep this spoiler free, basically nothing you wouldn't have seen in a trailer:
New armour is lame. The quests for it are pretty poor in describing the armour locations (I had to look more than one up, and was just like, "how does the clue even point THERE?), and the armour itself is all pretty boring effects wise. DLC1's armour was at least good early on, as well as giving a few extremely useful tools in general. DLC2's... even if you got them early, I don't think any would be hugely useful. Maybe a few would help occasionally, but it'd be a fairly niche swap to them.
The new story quest is huge, and really fun. This is split into three parts, and I can't go into too much detail on any without at least some minor spoilers, but in short... it starts okay, then gets quite good, and ends on a great note, even though the in-game reward is actually pretty lame. So yeah... not gonna spoil any details, but for those who want to keep everything a complete surprise, I guess skip the spoilers.
Part 1:
This takes place on the Great Plateau - basically, you get put in OHKO mode, so you kill everything in one hit but you also have only 1/4 heart and no healing. It's a fun little challenge, but I feel like they should have banned bows. New shrines as well which is fun.Part 2:
Trials at each Divine Beast. They're not all that long or difficult, but they let you do a few more things in the world and have a few puzzles to solve. Plus you get to hear more of Kass, and get cinematic cutscenes. The reward for each part here is nice as wellPart 3:
The new dungeon. It's similar to the divine beast dungeons, and has a new boss fight at the end. The puzzles here are pretty fun, and the boss fight is probably the single best boss fight in the game. Possibly one of the hardest, too - though with my postgame complete Link it still wasn't "hard".All in all, a pretty rewarding bit of content.