What action should I advocate for my religious community to take?

I am someone who thrives off negativity, but most people are highly averse to negativity. They may be willing to tolerate some negativity, but if you have not suggested action to take for your criticism, they will say "It is not productive to be against everything - you should be FOR something"

I imagine this is why r/FreeSpeechBahai has in many ways been a failure. Although there is a handful of somewhat regular posters there, no one other than myself seems serious about reforming the religion. And I think the reason is that since it is a virtual community, there is nothing you can really "do", so people don't see much of a point.

Local communities on the other hand, there are actual opportunities to "do" things. Which makes me wonder, what exactly should I "do" in my local community? Ultimately I want for the Baha'i community to become a place where I can get a wife, but it will be difficult to get the rest of the community to be enthusiastic about this. I feel like I will need to start with smaller goals, with more general appeal. The question is, what?

The thing that I have heard several Baha'is in my community advocate for is to bring more young people back into the religion, and this something that would help me get a wife so I am of course on board with this. But I do not see a straightforward action to take for this. The root cause for why the young people left is the central Baha'i leadership did a bad job of running the religion, and forced people to stop all the local initiatives that might have helped keep young people involved. So I'm afraid I am afraid the first thing I see as needing to be done is to convince local Baha'is to start rejecting the central Baha'i leadership. Is there anything else I can be "for"? And then let's say I succeed in convincing them to break away. Then now what? It's still me and a bunch of old people. It just seems so hopeless.

I personally think adults are hopeless.  Most people are just too stupid to be reasoned with.  They absorb beliefs and culture by osmosis.  So the right approach is to focus on children.  See my post Making a Difference.  Running a full school is probably too much to begin with.  But you could offer classes on weekends.  Maybe a class on Bahai and a class on Go to teach critical thinking.  That roughly corresponds to the Arkian approach.

There are a few Baha'i children in the community. About 6 in the 0-10 age range if I am counting correctly. Which, when I think about it, is surprisingly a lot, given how elderly the rest of the Baha'i community is.

The current approach to educating children, which all of these 6 children are involved in, is called the Institute Process, and it is developed by the central Baha'i leadership. The Institute Process leaves out mention of God and the prophets in most of the books, because the Baha'i leadership says if God is removed this will make it easier to proselytize other people's kids (because many non-Bahais don't want to send their kids to classes where they learn about "God"). Rather than teaching about God, the Institute Process teaches kids to blindly follow "virtues" like kindness, caring, loving. Nearly all children who grew up on the Institute Process ended up leaving the religion, including my younger cousins. So education does seem to be a serious problem in the Baha'i community.

There are things in the Baha'i writings contradicting the Institute Process approach (as do the verses you quoted from Deuteronomy), for example:

"That which is of paramount importance for the children, that which must precede all else, is to teach them the oneness of God and the laws of God. For lacking this, the fear of God cannot be inculcated, and lacking the fear of God an infinity of odious and abominable actions will spring up, and sentiments will be uttered that transgress all bounds."

--Baha'u'llah

So I could attack the Institute Process with this quote and make arguments for why this is why the young people left (I mean, if they feared God they would probably remain religiously active), and say that another approach to educating children must be taken. So yes this does seem like something practical that I can lobby for. Only issue is I am not exactly good with kids, and it doesn't really benefit me or help me get a wife, so I would really just be doing it for the benefit of future generations.