A nice map, I enjoyed it. Some good stumpers in there, and I like challenging maps.
I beat the second room without the cube. It's much simpler than it first appears to be. Here's how I did it:
At first I thought you had to bounce it off the angled corners, but then realized I could portal myself to to the ledge directly across from the ball launcher, then put a portal on the far wall (the top left of the ball launcher wall) as high as possible. After the ball has gone through, I simply replaced the portal on the same wall, but lower, which makes the ball higher when exiting the other portal (which is still facing the ball launcher). When done properly, the ball should bounce off the launcher directly up into the receptacle.
If this was not the intended solution, you've got to somehow make the ball last longer, and then I'll try it again using the slanted corners.
I do have a few qualms however. In the first room, it is not very clear at all what you are supposed to do. The only clue is the arrow pointing to the "target goo", but that is confused by the other two pointing to the later needed hole in the wall. You need to somehow hint at the solution better, or introduce the mechanic somehow.
In the second room, you really should fix it so people can't get the cube in there.
Edit I see you fixed this by slamming the door shut as soon as you walk in the room? Nice. 
And lastly, the flinging puzzle is simple, but very tough to do. Consider changing it to a combination puzzle, or making it about less reflex and more puzzle solving. It's not necessary though, just a suggestion.
Other than that, awesome job, one of my favs. 