Hi @Five_Alive !
Here’s my “application”, and yes: I’m posting this as a TeamSpeak addict:
- Overall, how long have you used TeamSpeak for? (any version)
I’m using TeamSpeak since 2010, and have also been a very long-staying and active user for now. I used it for windows, linux and later for android as well.
I mainly flew into TeamSpeak, and used it very active. Only a few years later, I took a look at the TeamSpeak 3 misc and also have made my own add-ons, which I publicated officially on myTeamSpeak. Oh, and I’m also moderating the german channel of the Official Public Community Server.
- What OS/OS’s are you currently using?
Windows (10) right now primary, and sometimes Linux as well. I can handle both operating systems very good. I’m a android developer as well, but I didn’t use the mobile app so much, only sometimes.
- Are you currently a server owner, an active user (but don’t run your own server), inactive, or a mixture of the prior?
Yes. I’m currently leading an international public TeamSpeak server as well. And in the past years, I also managed servers for myself or other peoples, mostly for friends. ^^
It was also very active, with users, licensed and passioned too much.
- On a scale of 1-5 (1 being low and 5 being the best), how would you score your technical knowledge on TS?
5! Pretty sure — I may cannot go 100% into details, but I can sum it up.
More information's about this, open >> here <<:
When “5” sounds unbelievable, we can set a 4¾ as well.
There could be some gaps in my knowledge. 
I know quite everything about the TeamSpeak software, history and also about the company somehow. But the basic’s are 100% sure at the moment. I also tested the TeamSpeak 5 Alpha client from September 2019 — March/April 2020. And I’m also still testing the TeamSpeak 3 client right now in the latest alpha versions.
More about my time in the old alpha stage, open >> here <<:
I’m also able to keep the details secret, with contract or not. If you want to hear more informations or stories about my time in the alpha stage, feel free to get in touch with me. You can also ask me anything about this topic, it might be interesting. 
- Optional question - If you could add something that doesn’t exist on TS currently, what would it be and why?
Personally, I would make some changes. The biggest topic for me was the public server list, and also the country database. But anyway, I’m still interested to test the alpha stages again. 
NEW:
(6.) Supplement
I’m a huge fan of TeamSpeak and its software since many years now. I registered for the beta in early 2019 for the beta because I was very excited to test the brand new TeamSpeak software at this time. And recently, I’ve got also alpha access for some reasons. Latelly, because I’ve never signed an NDA at this time, I wasn’t able to get access to the new alpha-channel-stages.
Mostly, I love to explore softwares and see how their «trip» goes on, over the next years. I’d also like to hunt bugs, and of course to report them directly detailed and also very carefully explained, if it’s wished.
I really hope that you've enjoyed my tiny application. It would be pretty valued, when I get a response from you guys. I look forward to a nice conversation, hopefully going on. (^_^)
Kind regards
MCG