I’m unsure of how many people are behind the Talent Hub, but from searching on the forums, those people have been listening to the community. They care about the project and seem to have learned many lessons since they started working on it.
I don’t think Roblox has a job specifically for the Talent Hub, but I don’t work at Roblox. I know there are many teams that have to focus on many thing. The staff to community ratio is insane along with the feedback from said community. They have a lot to go through and work on. Maybe more staff focusing on the Talent Hub would help, but I don’t think throwing more people at this is the ‘solution’.
Maybe Roblox needs to up the developer relations team. Someone’s got to search/sort through all the feedback, effectively communicate with other teams at Roblox, and then communicate back to the community. I’d love to do that, no positions open at the moment. Anyways…
Here's my response to your points: (good for others to know if they don't ig)
There’s a feature request for this, I recommend supporting it: Allow job postings to have multiple forms of compensation
On my creator page, I have the forums set as a preferred method of communication.
Also, this is from 2021, but might be relevant:
I don’t think I’m allowed to put my business email, but you can find mine via my YouTube. Also, Roblox bought Guilded and thus that is the go-to communication platform, or it would seem. Which makes it especially odd that I can’t add that as my preferred contact method, or a link at all.
There’s no feature request on it yet, I’ll be sure to make one about Guilded not being an option. Would you say adding that would suffice as a solution?
The option is only helpful if people use it though. 
I’ll refer to the following again:
Get rid of the chat filter in the Talent Hub - #16 by peraldon
You could also look at peraldon’s activity on the forum for more update info if you wish.
Would a filter for age help? How in-depth should that be?
We have the Verified filter, which I feel helps a little bit. You could include in your job post in the requirements section, in text that you write, that you only want 18+ or whatever.
custom put in
It’s actively annoying to scroll sometimes due to the black bar at the bottom that I see on my PC. Mobile is mostly great imo. It used to be the other way around.
Understandable I think, but I feel making your own website for a portfolio would be best for the most customization. If there’s anything specific the Talent Hub doesn’t have and you want it to have that thing, make a feature request about it. First make sure to research and make sure someone didn’t already make a post about what you’re asking for though.