1. Make this permanent. This is not directed at a person who has no control over decisions that are made but at whoever makes the decisions. Decide now to make this permanent to stop stressing people out over the indecision. It’s great fun.
2. Thanks for having world 1 completeable (is that a word?) still. I am much slower at this type content than many and got a lot of world 1 done (maybe half?). I love that I can still do world 1 now. My goal this time is to complete world 1. I may not even get to world 2. I like that I can do that. Please continue this. 
3. Make the rewards permanent. I got the 2 rewards that I wanted the most the first time around. I earned enough for the backpack and luckily got the shield (the one weapon I wanted most) from a chest. I would like to be able to earn the others from world 1. I would suggest that you think of some mechanism to tie the rewards to the world that introduced them – that is, world 1 items are earned from doing world 1, etc.
This is especially true since I don’t plan on getting world 2 done this time round.
4. Living story in general – please stop waffling about content. Make a decision on whether something is permanent or not and tell us up front. I see that you are slowly moving in that direction and hope that you start minimizing one time content and maximizing permanent additions.
5. I know you aren’t supposed to call out people specifically so – I would like to thank the “not mentioned by name” designer/dev who works on SAB and also the JPs and interacts with the community in such a positive way. This is content that I enjoy but am not really good at (fine motor skills aren’t so great). But still I enjoy and appreciate it. Thank you.
Edit: Perhaps world 1 old skins could still be a random drop from the boss chest at the end?
Also, I would encourage pursuing a progress reporting system for letting you know how many baubles, kills, etc. are left. This applies to LS in general. The invasion completer needed this, other content needs this. In general, anything that you need to complete a certain number of needs to let you know how much progress you have made.
(edited by Katz.5143)