New maps has a cool way of passing information, but classic maps is more reliable for PitchPeek. If you're having trouble with new maps urls, switch to classic maps and try those links.
I created this website one weekend, just because I wanted to be able to make better tours. It's free, and I have another job, so this isn't something that is a high priority right now. There is no warrenty of fitness with this software, and there is no support either. So the lack o' faqs is probably just because this project is so new or because I haven't updated them in a while.
I always embed at 16:9, and in every preview or embed on, I used the 16:9 aspect ratio. You're free to embed with any height and width you want, but to have it match what you were seeing when you created it, go with 16:9.