The patch sent out today made the online so much better. I didn't have a single problem today.
I published my first level today and got some nice feedback. So far most users are describing it as "Pretty" or "Beautiful" but I did get one rubbish rating.

As far as I can tell the more people use a word the larger it get's so the word pretty was big but rubbish was really small. :D
I didn't get it exactly how I wanted it but I came close. There were some things I did that I couldn't go back and fix without starting over. I'm pretty happy with how it came out though.
Here's some tips for anyone who is feeling frustrated, maybe you can avoid some of the mistakes I made. Unless something needs to be connected, don't connect it. It's not very fun when you need to fix one thing and you lift up the entire level. As long as your object is heavy it won't move when people are playing the level. Tying everything down will just create a headache for you.
Play the story mode thoroughly. The more items you have the easier things will be. I spent my time the other day creating a object only the play story mode again and find that what I needed was already there.
Play all the tutorials. The ? mark that appears in popit, click it until you've done them all. This opens all of the tools that you might think are "missing".
Don't use all of the 3 planes unless you have to. Similar to connecting everything only use 3 planes when you need to prevent people from falling, for puzzles, etc.
So has anyone else put up any levels yet?