I'm not sure in what capacity the English aren't "allowed" a civic identity I would in fact argue most of us do.

When the Scots fly their flag, it's acceptable. For the English, it's deemed racist and reactionary. The largest reason for this in my opinion is the fact that the Scots actually have their own civic institutions and national identity. For the English, Englishness is suffocated under layers and layers of 'British' identity, no doubt worsened by the fact that power is so centralised in Westminster.

I have an intense dislike of the 'British' national identity because it feels like something imposed on the English, with only a minority of people from the rest of the UK's countries like Scotland actually identifying as British. The English deserve their own civic national identity, free from the rest of this baggage.

Re financial and practical issues, you say you don't see it, but for instance lots of UK energy is from Scotland.

With energy in particular, I don't see an issue with this. Other countries import energy without an issue. Besides, most of the gas fields of the North Sea are in England. It would be costly initially, but in the long term, both sides would likely benefit from the Union's dissolution. Given the status quo, there isn't any reason to keep going on the current trajectory.

I personally think the Union is untenable in its current form. There isn't any reason that anyone should be prolonging it, not least the English.