There are a lot of challenges for those people who will try to make their own indigenous language coin. Some of the dangers are obvious, some not. Below are a few things that should always be kept in mind.

False Federalism

 Any distinct, independent, sovereign tribe with its own language has, or will eventually have, border issues with other tribes. 

The natural origin of a federation or 'federal interest' is in those sovereign tribes that intersect, whether in finances, physical boundaries, resources, whatever.

Modern 'industrial' consumerist societies have seen the emergence of a fake 'federalism' that is not a composite of real tribal interests, but rather a synthesis of artificial corporate interests and misguided ambitions from individuals who lack awareness of a tribal identity. 

The United States is one of many examples of this unnatural federalism. Created by individuals who understood the proper role of federalism, the United States has since been hijacked by ambitious individuals who try to "mold" the original entities to suit their ambitions. The end result, the only possible outcome, is the death of either the parts or the whole. 

This is something so well studied, and so obvious, that it becomes unhealthy entertainment to some observers, like watching an injured shark eat its own innards. Any place, any country, where federal authority is considered more natural or basic than tribal authority, will not survive.  Any coins, currencies, issued or strengthened under federal authority will lose power naturally over time. 

Unfortunately for some countries, it has become the rage of the day to promote 'federal power' as some sort of 'parent function' in society. The result has been a plethora of idiots marching around in circles, using gangster tactics and contrived 'authority' to promote themselves as 'guiding' those who they harm. 

 Invisible Surrender / The Biggest Hazard.

The single biggest hazard for Native Americans trying to create an economy from scratch is that it could be a derivative of the U.S. economy due to a fear of intervention from the U.S. government. Today there are lots of indigenous group, enterprises etc that are entirely a product of interaction with and pressure from a 'federal' government or conglomerate. 

The goal of the melting potters has always been to draw others into their cultural mishmash by using subtle violence, threats, gifts, social pressure etc. In case that video gets deleted or misdirected, it is the Wikileaks Collateral Murder video, a ridiculous example of the United States trying to use language to get Natives and youth onboard the national darkness. Reading comments posted on the video explains some of the trickery. 

A Native coin should be entirely about, by and for Natives. There should be not the slightest respect paid to any outside government. 

Ideally at some point there will be a federation of economies, including many tribal coins that are independent but cooperate with one another, along with outside coins not focused on language, including fiat. Inclusion and tolerance are virtues but contamination is not. Natives in the Americas should set a high bar for turning back cultural destruction and creating environments which help recover what can still be saved. 

There will always be outsiders trying to profit from your coin and economy.

This website, for example, is anticipating a likely development in the coin economy, and is trying to provide helpful information, but is made by a speculator who profits from coins and might well take advantage of some coin or group if the opportunity arises. Nobody but you should be trusted by you to look after your interests. 

Coin promoters and groups are notoriously predatory. 

Unless you know the person you are dealing with, you should expect that most of the outside people trying to get involved in a coin made for an insulated group, such as an indigenous language coin, are there for profit, or worse.

There are enough public resources, including websites etc, that a local group should not have to deal with any outside parties in the creation, start to finish, of their coin.

If there is something about your coin that requires an outside expert, or any outside assistance, step back and wait for somebody more competent to make your coin without outside help. The only exception is like minded groups, such as other Indigenous groups who are making coins for a comparable economy. 

Be wary of discrete interference.

There is no question whatsoever that anybody involved with indigenous coins will be monitored by various agencies. If you are part of any indigenous American group then you are probably aware that Native groups historically are among the most monitored and surveilled groups in the United States.

There has never been any group that has been perceived as such a threat to the United States as indigenous people, and an indigenous group that is contemplating making a currency to defend its language and culture raises that threat to another level. The era of quietly arresting a few key leaders and putting them in jail for decades on dubious charges is probably largely over, thanks to the internet, but the danger is not gone.  

Any indigenous language coin will only help keep its respective language alive as long as distribution supports that.

Most likely indigenous language coins will have significant support from outside groups, and there will be a lot of pressure to profit from that. Outsiders will want to buy the coins for speculative purposes i.e., long term profit, but speculators can slowly draw coins out of local hands until the local economy is vulnerable to attack by a larger economy.

One simple reality is that a large economy will always consume a small economy if it is profitable to do so, and it always  eventually becomes profitable. Once you have surrendered some of your economy to outside control, you have surrendered all of it.

A simple solution is a very long slow emission of coins. If only a tiny percentage of total coins are created in the first several years of a coin's life, and if future distribution is securely limited to Native speakers, then this risk is minimized for the time being. The mechanics of that distribution would determine how well the coin would be protected in the future, and that would have to be figured out coin by coin. There will be attacks on all coins at some point, and this type of coin is likely to be attacked by more sophisticated threats, so it would have to try to put in protections that would anticipate those threats.