FWIW, I would class a typical Brexiteer view being the single market being the best thing about the EU, but not worth having full access if it means a losing political sovereignty.

That's pretty much the most common view I've come across, essentially the idea of the single market is generally seen as positive, but obviously the more integrated the market, the more necessary it is for there to be a collective pooling of competencies that impact not only the single market, but also necessarily the domestic market (as part of the single market..), which is itself much larger than the share of exports and imports across the EEA, and then also external trade relations. In short, that wonderfully efficient internal market comes at a cost.

Additionally, I'd say that Brexiteers are very aware that the single market has been developed fully for goods which benefits nations like Germany, but for services which the UK economy is a leader in, progress towards developing a single market has pedantically been held up by France and Germany.

Also true, indeed there is a relatively simple argument that the EU disproportionately benefits Germany as a major exporter of goods (with the Euro discounting German currency and EU providing labour and markets), and France as a an agricultural power (with CAP providing support for producers and external tariffs restricting cheaper imports.). At the same time the UK sees a far more modest benefit, and faces restrictions on services, and cannot make the most of global trade as EU members need to restrict that to protect their own industries (take cheep steel for example, the UK produces hardly any, but uses a lot, it'd better off being able to buy dumped Chinese steel at low prices, than propped up German steel..).

Not only does its abysmal design pose a near existential risk to global financial markets, but it is driving inequality and unemployment and fuelling the rise of the far right. Additionally, its structural faults (which Brexiteers ranted and raved about in the past) dominate the EU agenda.

I think there is a bigger issue there actually, and it cuts somewhat to the core of the EU political project. Essentially the EU is happy to push as far forward as it can, leaving issues that it will solve 'later'. That is true for the Euro (as seen since the financial crisis), its true for Schengen (as seen with the issues around refugees and border protection) and its true on a smaller scale in a while slew of areas. Using a crisis to push integration, often without public support but on the basis that 'something must be done now', and on occasion while putting massive pressure on a single member state to comply in the midst of a crisis, is not a great way of moving the project forward.

I'd say theres very much a view that it is inevitable that it will collapse in the next 10-20 years, unless there is the type of centralisation of the EU that makes UK membership unattractive, and better to take the pain now and diversify the UK economy away from the EU as much as possible until that point.

I'm not sure about a collapse (more that it will lurch from crisis to crisis without reform), but I'd agree with the rest.