Im not a developer...
Well but If I would
This is what I Will do it :
I create coin name it fiat stable. Its valued 1:1 to eur and 1:1 usd. And Transaction fee always 50 cents and maximum of 3 minute Transactions.
That's Simple!
the problem is that most people are focused on making hodl and do not use cryptocurrencies to shop, there is LTC for example which is faster than many currencies, but then why is LTC not on top? because it copies bitcoin and people feel more secure making bitcoin hodl and for the LTC case people used it when they want to transfer coins from one exchange to another. this means that many developers are not focused on the question of speed and low rates, they focus on creating things that will attract investors.
Just stick into the trusted coins if you are feeling so hard to find the coin that can be trusted and i think that will be a very easy task to be done by you dude. there are a bunch of trusted coins on CMC. If you didn't have enough knowledge about how to deal with the new coin and then you should try to avoid it rather than put yourself at a big risk with a very big chance to lose your money instantly.
there are currently hundreds of good altcoins, the person just has to choose what he thinks is suitable for the purpose he wants to use
for example:
if the person needs fast altcoin, then they can choose fast altcoins like LTC and others
if the person needs altcoin to make hodl and make a profit of 3X the person can look for altcoin that serves this purpose