Be nice. Or else.
How do you make money for this tool to be sustainable (future updates, improvements, etc)?
You just have to choose 1 and stick with it. Later on it will be easy to switch. Personally I would choose the one with the most momentum/community behind it these days. So that's ReactJS (but this is still frontend). As far as backend goes, NodeJS/Ruby on rails is up to you. I started with Ruby on rails, if I had to do it again today alone, I'd probably go with NodeJS.
I think you ultimately need to learn all, and it's worth the investment. Projects/startups require a lot of iteration. You're also in it for the long haul, so spending a few years learning all of these skills is worth it. The best way to learn is by building tiny projects and getting them out there. Then you'll start to meet other like minded people to team up with.
Try it out at the microsoft store, if it works well for the jobs you need done, why not?
Can you expand on what you mean by visually show the ML solution? Usually the ML results in a simplified result/classification. Are you looking for examples / diagrams of how it worked in a specific system? https://medium.com/@ageitgey/machine-learning-is-fun-80ea3ec3c471 is the best overview I've read on the subject. He gives an example of figuring out the price of homes.
How big is your company and the team you work on?
I don't get it, the product is free for individuals. Teams can afford to pay for this especially on the company's dime. It's crazy that Sofya and her team even poured years of their lives to provide such an awesome service like the noun project (for free). They've already given a lot to the design community.
Now imagine if they had more money, how much more they could push the industry forward. As a creator, it's important to remember that real people make the things we use, including this free designer news website. I know it's the norm to not pay for software just like its the norm for designers to not create products people pay for. We need to use our skills to create better business models, sustainable products, and offerings for users, so that creators like Sofya can build even more new ideas.
If we want our toolset to evolve faster, we need to support the people that are putting themselves out there to bring change. The community constantly talking about a tool and sharing it with others is much more powerful than you think.
Thanks for the writeup! I think diving into anyone of those topics would make for a great post. I'm particularly interested in how design works with the marketing team around growth and getting new users
While this is true, the market is huge! People will use what they know of and what solves their problem. They won't only use the product with the best UX