A few notes after reading...
1. I think that pretty much everybody wants to go bigger as soon as they finish!! LOL My pond is 1,000 gallons, and I really want to double that. But taking out the fish and starting over is a bit overwhelming.
2. I'm just now starting the planning of a water bog, and I wish I'd done it in the beginning. It'll look a lot better, and be a lot easier to maintain!
3. I love how you hid your liner, mine isn't hidden well at all (another reason I want to rebuild).
I totally agree on plants, it'll make a world of difference. When you do...
A. Parrot's Feather helps keep nitrogen in check, but it TAKES OVER!!! I bought like 10 sprigs when I first built the pond, and now I literally have to fish out 4 or 5 wheelbarrow loads every year and just throw it out. And I still have too much left! It wraps around my water lilies and pickerel rush, and I can't get it out without damaging them. If you're within driving distance of western NC, you're welcome to come get as much as you want
B. I strongly recommend putting plants in pots! There are some that do fine if you just toss them in, but they'll divide and divide and divide and take over. Or worse, they'll grow in to your liner, so when you try to take them out you end up damaging it. So trust me, spend a few $$ and some time on getting everything properly potted.
How deep is the pond? I don't see where you've said. I did 3' with the hope of giving fish room to dive if a bird came to eat, room for water lilies to grow, and in an attempt to control some of the algae.