Nope
Yes. I don't think it's allowed in Japanese Garden but people do it anyways.
It should be okay without a permit, since you're not having an event or selling anything.
Yes you can take photos! I see it all the time by the waterfall in the park
Ive seen all types of photos taken here not sure about the need of a permit. Your photographer should know or maybe call the city of houston.
Thanks! Your answer is awaiting moderation.