That sounds good on paper, but the chances that someone else will pick up the ball if they abandon it, even if it’s open source, are very slim. If you care about keeping it alive then paying them is a more effective strategy than hoping for random volunteer work by internet strangers.
You, on the other hand, have good chances of being able to learn new tools. So I think the need for this security is exaggerated.
Sure, as long as it works. Software has a tendency to stop working on newer OS:es or become subject to security exploits though.