To take independence for Scotland first, I for a long time was a federalist, ideally I still would be. However, we went through a period where we centralised UK powers reducing local democracy and then along came the Scottish parliament. After a number of years, it was clear that federalism wouldn't happen (the powerhouse of the North which is closest in recent times looks a piece of window dressing). Also the parliament lead us to not just a democratic deficit but a responsibility deficit where no one seemed to be really responsible. Along with the historic differences as regards law and education, it seemed to me the best thing on offer to address a problem apparent for a hundred years or more that was on offer was independence.
I think a large part of the issue is the ability for the SNP to blame Westminster which plays well to a Scottish electorate that a large part of hate the English.
The cure for that though is independence
Note I thought that would also deal with a mis-shape in the democracy in the overall UK or at least kick off dealing with it. It was a pity that the unionist parties didn't pop a devo max option on the ballot paper as I think given it was policy for some and would have addressed the responsibility deficit pretty fully, it would have given them real status in Scotland and allowed them to fully expose the ' don't frighten the horses' approach of the SNP. The Vow with its vagueness and being all things to all unionists has just ended up with a further gap in democracy not having been voted for and no one really knowing what it meant.
The vow was more powers for Scotland; Scotland is getting more powers. You can argue is was vague but the Scottish voted for it.
This may lead to something useful but to take an example you mentioned elsewhere, the income tax bid by Labour illustrates the mess. Fair enough it was an attempt to regain their anti austerity credentials but it was always doomed. That wouldn't be bad if it didn't show up the current problems. So the Scottish Govt can only adjust all tax bands the same, so it looked as if they would end,up taxing the lower rate tax payers and regressively at that. Instead of having planned to deal with something that had to happen, they then ran round talking about a rebate system that appeared to cost more to implement than they were going to raise. As the further powers crystallise it may be that this sort of issue can be avoided, one hopes so.
Following the Smith Commission won't the Scottish Govt. get 'The ability to set Income Tax rates and bands' (from wiki).
The case for staying in the EU to me seems to be that the democratic deficit is one that could be addressed internally, it is currently much more federated than the UK ever could be. Also many of the decisions taken, such as the refugee crisis which is likely to get worse in my opinion, but also questions of what defense means, seem to me to need to be taken in a large block. Larger than the UK and in one that because of how it is currently constituted has the means to develop forward.
A common defence policy is unworkable isn't it. I would expect a government to be able to control immigration, the electorate voted in Cameron on his 'no ifs or buts' promise but he is unable to deliver.
I worry that the UK would become essentially a reaction to the loss of its central role that still haunts the rhetoric of many leavers. That along with a strong hint of less support for workers and deregulation that will only help the rich. And yes there is a problem with the sign up to TTIP with staying in the EU, I just don't see that following with less protection in an out UK.
If Corbyn got elected then this would solve that issue. I'm sorry but if you are going to address the democratic deficit issue what you see as an issue is irrelevant, its what the electorate wants. So for example the electorate might not want TTIP they can't vote for anyone that can stop it whilst in the EU.
One thing is I'm not wedded to either side emotionally here, nor do I think it is clear that there is a right side. It's an accumulation of guesses and having to come down on one side eventually. One thing that I suspect was a mistake from Cameron was the timing. It means for us in Scotland, Wales and NI we will follow parliamentary elections with another campaign. I think the vote may be down simply because of boredom. Given the current polling that is bad news for stay in the EU.
It may be a bad judgement call but if the late Summer news is filled with stories of another migrant crisis or Germans rioting in protest of immigration or the Euro collapsing then Cameron might have timed it just right.