Aki: "Only one. Why is your hairbrush in the dungeon?"
Glimmerwing: "So you can go get it for me, dummy. Bye-bye now!"
That fall hurt. Fortunately, your dungeon interface didn't appear until after the landing, so your HP is untouched. Now let's ... HEY! Someone retconned Spell Slot 1! It now has Burst_Scatter instead of Combo, and the sub-slot formerly taken by Combo is no longer comboed with the other spell slots. This will probably be less confusing.
You feel a slight urge to kill the slimes to collect their remains. It'll probably get stronger as you get closer, making it difficult to merely jump over them. Carrying a bunch of bottles of slime around might get annoying, depending on how many slimes are in this dungeon.
Red slimes are not dangerous. They tend to move randomly on a flat surface. Their touch is painfully acidic.
You could climb over that small wall in the middle, although you're a bit vulnerable while doing so. (You're not sure why there are even ladders here. You're perfectly capable of climbing up a small ledge.)
There are a pair of empty vials above you, which you would need to get in order to gather any slime remains.
As there is no key on this level, that chest is probably unlocked.
Your spells generally cost 1 MP each, but may be strengthened by paying more. If you run out, it will slowly recover from ambient magic, up to a point based on how much is in the area. This area is magically weak.