Personally I find the pattern sequencer to be the weakest link in my Renoise experience. That said, I’d like to make a couple of suggestions.
I’d like a pattern list, like the instrument/sample list, that shows a summary of all patterns you’ve created, what you’ve labeled them as, and maybe an indicator for whether they’ve been used or not. You should be able to click on any pattern in that list to play it, duplicate it, edit it, or delete it. From that list you should be able to drag and drop each pattern to add to the sequence and drag and drop to reorder patterns in that list (just like the way the DSP chain works only each node is a pre-defined pattern).
I’d LOVE to be able to have more that one sequence on the go at once. Back in the Impulse Tracker days, I could build as many sequences as I wanted… I just had to leave a blank spot between them and they were treated like different songs. This meant that I could experiment with different orders without having to delete the previous one, or load/save different version of the song. If I started to play a piece of a sequence that was isolated from the other pieces by blank space, it would just loop within itself. I could build the verses, different choruses, intros and endings and then piece them together in different ways to see how they worked.
I find that it’s very easy to get one master-pattern created with all of the ideas for your song, but I find it completely un-intuitive to build the song and tweak it from that point. I’m NOT saying that there currently is no way to do this. I’m trying to sugges something that adds more flexibility (and simplicity!) to the pattern sequencer and that builds on some of the concepts that are already present in Renoise.