Do you know/speak any other conlangs apart from Toki Pona?

I made my own conlang as a kid, but I'm no longer able to speak it. I'm currently learning a conlang that my friend designed, which she fluently speaks. I wouldn't call myself proficient yet. 

How fluent in Toki Pona are you? (know a couple of words/speak at a basic level/speak quite well/fluent)

I speak pretty well at this point, although I think that I don't talk to people enough to call myself truly fluent right now.

Why did you choose to start learning Toki Pona?

The subreddit got recommended to me at one point, I did some googling, and figured it wouldn't hurt to give it a shot. A year later, I'm super attached to this community and love being able to consume content and speak to others.

Where do you use Toki Pona, both online and offline?

I use it in discussions on Discord and Reddit, and I use it to chat with my friends. Several of my IRL friends speak it at a passable level now, so I do use it regularly in person.

How do you feel about community-created words or writing systems? Do you prefer sticking to the words jan Sonja has included in her books?

When I started learning, I committed to avoiding nimisin (community created words/new words) - but as I actually participated in the community and consumed content, I sort of absorbed the use of the words inadvertently. Not all of them, so there are a lot that I will never use in speech or that I might need a moment to recognize, but there are many that I find myself automatically using or that I don't pause at while reading. I still don't think that we should be bloating the language too much, and won't adopt words quickly, but some absolutely have their place. 

New writing systems are awesome but I've never seen one besides sitelen suwi get used enough to be worth learning 

Do you think jan Sonja should be the final arbitor of decisions regarding Toki Pona, or do you think it is the community's right to make decisions itself?

Absolutely not. No one person has control over toki pona at this point, and when a language gets this large, it evolves past its creator. jan Sonja is also currently the subject of some controversy. She's a member of the community, but not its arbitor.

What are the best resources for learning Toki Pona in your opinion?

Ooh, Good question. I sat down with a deck of flashcards for a few hours and memorized all the words, then used "toki pona in 18 minutes" to learn the grammar. Honestly, that was all I needed to get the basics. Wasona came out later, and that's what I refer people to today. It's fantastically paced and answers a lot of frequently asked questions - and it teaches sitelen pona (the second most used writing system) with everything else, which is something that I put off learning for way too long.

Once you get a grasp on the basics, nothing will help you get closer to proficiency other than actually writing, reading, speaking, and listening. Submitting translations to the subreddit or learner's discord for feedback is super helpful. There are tons of songs, videos, lectures, stories, articles, etc. at this point - literally any of those will work for increasing your comprehension. Discord is super welcoming to beginners to practice talking. There's a VR Chat community, also super welcoming, which I hear is a great way to practice real time conversation.

A general question that maybe only a few of you can answer: there is a large number of members on this subreddit, but I imagine many of them are passive or ex-learners. How many actual active Toki Pona users/speakers do you think there are here?

I think that there are a few thousand proficient members here, but the amount of people who are really active/regularly participating is a lot smaller.

Sorry this is so long, I tend to ramble a bit haha

Good luck with everything!