"Why not be completely crippled by bad randomized starting position without luxuries instead of just having to buy goods and be completely dependant on good will of other players."
Is what I read in this.

I am not exactly sure what you are arguing about. What is the point here ?

Well then ... that's exactly what the civic should address.

Not having luxuries or trading partners. Stability ... from ... faith?

https://c.tenor.com/DY0U3qaGuD0AAAAC/chess-checkmate.gif 

I don't think there is an argument, but from the OP I find it difficult to comprehend in which part do you state "no trade = stability from religion"

Religion seems too easy mechanic to manipulate in your favour, even if you are behind, you simply adopt the top religion next to you and get maxed tenets or whatever support you are suggesting.

If it's remade to be a civic you have to make a choice and it requires at least a token investment of influence. Maybe the choice is between your 'founding religion' and 'trading' so that it's not quite a non-issue. But there seems to be an over all consensus that trading routes by default aren't a satisfying part of the stability mechanic. It's not a fix exactly, but a slight improvement.

I think it's still kinda off point, investing 7 influence in a civic that makes me choose between trading or having a religion means I would just pass on the civic and keep it as is.

What is mostly discussed is that luxuries make the stability a non-issue, trade is mostly just a symptom.

Luxuries and how they stack both with stability and manufactories are obviously a big issue and need to be examined. But I do also think that trade is boring. There just doesn't feel like interaction, it's not an interesting investment like ES2 where you build trade routes that yield both dust and resources, you just buy buy buy as much as possible from other people. Again a lot of diplomacy besides the greivance system is really shallow, I hope Amplitude can make trade more engaging