Funny you should mention the fiscal difficulties of Welsh "Full Fiscal Autonomy" or independence, as today a major report came out of Cardiff Uni:
http://sites.cardiff.ac.uk/wgc/2016/04/ ... 7-billion/A Welsh budget deficit of 24% of GDP, compared to 5% for the UK as a whole.
In effect, taxes in rUK are used to allow Wales to "enjoy" public spending about 8% higher than the UK average, despite paying taxes equivalent to about 25% less than the UK average (due to lower incomes - as a share of GDP taxes are actually a tad higher).
Now thats not unusual in countries with significant geographic variances in incomes, and a redistributive state (and the UK is far from alone in that, although given the particular concentration of activity in London, it is a bit more noticeable than in most western-European countries). The North East would probably look similar.
Would Wales be better off now if it had had "home rule" all that time ago? Its hard to know for sure. One thing is sure though. It would be relatively easier for Wales to be more 'productive' than it is now than it would be for Welsh people to be 'better off' compared to now. Welsh GVA per capita is about 72% of UK average. Welsh household income per capita is something like 90% of UK average. In effect a lot of those spending transfers from rest of the UK boost Welsh incomes more than they do Welsh GVA. It would be easier for us to have boosted GVA above current levels than household incomes above current levels without such transfers...