You loosened the bolts that hold together the two sides of the caliper. There's an Oring sealed joint in there that opened up and let out the fluid as well as air into the caliper. As Torchy has already mentioned you adjust then only with the mounting bolts.

Again as Torchy mentioned the DOT 4 is very nasty on paint but it's no more harmful to skin than any other car oil or fluid other than battery acid. I wouldn't bath in the stuff but a little on your skin is no need to panic. If you get some on you just don't touch anything painted until you wash it off well.

An "upgrade" would be to switch to DOT 5.1 which has an even higher boiling point. Great stuff if you're a downhill racer or serious downhill rider. But totally not needed if you're just a regular joe that has some shred of a sense of self preservation. If you do upgrade do NOT go for the DOT 5. The ".1" makes a huge difference. 5.1 is a glycol based fluid same as the DOT4. DOT 5 is silicone based and if mixed with any of the other glycol based fluids will turn both of them to nasty Jello like muck. So just keep that in mind that 5 is bad.