E.g. Welsh white paper para.5.4 "Securely located within the framework of a strong United Kingdom, the Assembly will give the people of Wales a real chance to express their views and set out their own priorities."
E.g. Scottish white paper "The UK Parliament is and will remain sovereign in all matters...." 4.2
But it must be recognised that these are to some extent unrealistic and legalistic appraisals, for the UK Parliament will find it politically very difficult to change these arrangements once they are in place. So, it is possible that a federal type system of government will develop in time. This is especially true in relation to Scotland where the powers to legislate are reserved to Westminster not Scotland. In other words, one can say that the "normal" default position is that Scotland legislates for itself, and it needs no express permission to do so.
There is already much scope for clashes between the devolved bodies and UK bodies. How do we define Scottish or Welsh business? In Scotland, it is up to Presiding Officer of the Scottish Parliament to be satisfied that any Bill (legislative proposal) to be introduced is within its powers. If there is any dispute, it should be referred to the Judicial Committee of the Privy Council (consisting of 5 Law Lords). Presumably, a UK Parliament could legislate contrary to any decision. But it is not likely to be practical politically for Parliament to act in this way, and so it becomes very significant that it is the Judicial Committee, acting in reality like a final constitutional court, which is the arbiter and not the legislature.
There might also be economic rivalries between the UK and Scotland. The Scottish Parliament will be able to vary income tax by 3p. Most think that taxes will be increased - but what if it give incentives e.g. to foreign investors - this could cause disquiet for example in the neighbouring north-east of England.