Would there be any evolutionary pressure to become more intelligent or would it just be like Earth's ocean for ever?
I think it is very likely for intelligent life to appear given the condition you mentioned. They will probably look like the very weird deep-ocean creatures we have on earth since they evolved without any light and in almost the same condition you evoked.
could they invent any technology at all apart from simple things like using rocks to break open the shells of their prey
We could think of water as a fluid and starting from this it's not much different from air. Without any generally produced light to see far away the creatures would have to rely on their own bio-luminescent light. Which is costly in term of energy so I guess this world would be very very dark and would evolve way slower than ours.
Anyway why wouldn't they have the possibility of inventing technology. They could start by finding ways to get durable light generators (even if it's implying slavery). You stipulated they have hands so they can manipulate objects and combine objects together which means they have access to tools and by extension to any tool which works in the water. They can have electricity I think if they invent a way to isolate metal from water but electricity in this world would be tremendously dangerous since they evolve in a highly conductive environment.
Would there be any point in forming laws and governments or studying philosophy?
I would say yes. As much as here. But I bet it would be much different. They would probably see the ice as we see the sky at the difference they could "touch it" by "flying to it" unless you have some creatures incapable of swimming and stuck on the "floor".
Can anyone suggest a way that the intelligent inhabitants could create an advanced civilisation under these conditions?
Prehistoric age
Fire & Light
First of all they would have to invent a way to produce energy like we did with fire. Fire is prohibited though so they certainly will use some chemical processes. 693
If your crust is thermally active they will heavily rely on this. They need to build shelter, to produce food and to protect themselves from threats. This is totally achievable in the water.
They will produce their own light and it's very likely that slavery would be a consequence.
Communication
They would communicate through sound waves exactly like we do since sound evolves rapidly and efficiently through water. They could create a complex vocabulary base upon different wave lengths and "sounds" like dolphins and whales do.
Writing
They will have to invent writing so they can store information durably. This is not infeasible and they will start as we did: painting the walls of caverns.
Steel and coal
The difficult part is to forge steel. I don't think there would be any very efficient black-smith in this world and this a real problem but we could imagine they could have access a other options we do not know like chemical smiting.
Electricity
Like I said electricity is very hazardous in the water and I don't see how a water-proof computer would work but they might find a way - maybe by heating up water - to create little isolated gas-pockets in order to protect their appliances from the surrounding water. Those gas-pockets would very much look like our light-bulb. The environment will make electricity much more difficult I think but not impossible.
Science & religion
Science would not be very different than ours since it's not dependant on the context but is rather a theoretical concept. I think they would consider trying to understand what's beyond the ice crust like we tried to understand what's beyond the sky. They might have the same difficulty because of religious conflicts. They will be likely to consider the Ice Crust as a god and many rituals would emerge from this, like "touching the God upon our heads" as ritual for being a grown up. 790