Do you advise not stopping for red lights in case people don't see you stopped at them too?

No.

Ever driven at 40.00000001 mph in a 40 limit?

Ever sounded your horn whilst stationary on the road?

Ever stopped at the roadside and failed to turn your engine off?

Parked without your handbrake on?

Farted in a lift?

All irrelevant. What I do or not do is irrelevant to what the rules of the road are.

Your argument is that the laws should not apply to you personally just in case someone isn't paying attention. No different from advocating not stopping at red lights in case someone doesn't see you've stopped. Or maybe if the traffic stops on the motorway in a hurry and you're at the back should you should take to the hard shoulder 'just in case'? Potential suicide otherwise.
How about if you are the only car on an dual carriageway coming up to a roundabout and there is a stream of traffic crossing it? Same limit. Same rules. Same chance of someone not seeing you stopped at the give way (and of course the lack of a gap) and hitting you. Force you way on, drive through the hatchings, fk the right of way. Following the rules of the road is for suicidal losers after all.

Yes you should be prepared for someone behind not seeing you but that is no different from many other situations. You prepare, you plan an escape route, you keep your wits about you and if need be you use it and use it fast.

I'm hardly the best driver in the world but I've never had to stop at the end of a slip road (except when the motorway was stationary). Doesn't stop it from being the right thing to do and from being prepared to do it. If need be you crawl, do everything you can to not stop, or stop early with a run up still but if all else fails you stop at the give way line. Then it's no different from pulling out onto a dual carriageway from a layby (which after all has the same limit), you signal, hope someone will move over and when there is a big enough gap give it the berries.

Don't let the door hit you on the way out.

I thought you were going?

I do like to try and do my part.

I thought that the Police advise to use the hard shoulder rather than stop. Can anyone confirm ?

Since you are advised that after stopping on the hard shoulder for a suitable emergency you should build up speed on the hard shoulder before merging with the running lane, it must make more sense to keep moving on the hard shoulder than to stop before it. You could argue that it is an emergency.

Problem is the sort of slip roads where you can't see the approaching traffic until about 10ft before you are next to the dashed "give way" line. If you creep up to that and only start accelerating then you're not going to be going fast enough. So you turn up at full speed and reduce if needs be as that's easier/faster to do in a short space.

Take something like this: http://maps.google.co.uk/maps?q=newbury&hl=en&...

The slip is shorter than a gnats penis by the time it's straight. Before it's straight you can't use your mirrors to see a gap (because they are not pointing towards the carriageway). So you're accelerating hard, around a curve, which means you need a reasonable focus on staying on the road, and possibly trying to get the odd glance over your shoulder at the same time. Add in you get clumps of trucks previously stuck behind a slow one coming up the hill previous, and now all free-wheeling downhill while being overtaken by cars. You can find situations where by the time you can see there are no gaps, your options are stop and wait for a big gap behind the trucks that you can accelerate into, or drive into a truck.

Take this one: http://maps.google.co.uk/maps?q=m5+j2&hl=en&am...

Now you are coming up from below the motorway. Your mirrors are about 6ft lower than the camera remember. Until you are past the "wall" you can't see the traffic on the carriageway out the window or in a mirror. If lane 1 is full and no gaps. You can stand on the brakes to try and stop early to give you a run up. But those behind you can't see why and may not have anticipated you doing that. They stand a good chance of hitting you. So you slow down gently, and hope a gap appears before you get to the end. If the people in lane 1 are not good enough to open up a gap for you. You are supposed to stop and wait for a gap. Which'll be a nice gentle manoeuvre that people behind can anticipate.

Thundering on down the hard shoulder with no sight of a gap is no different to just using it as a lane. If there's no gap where are people expecting to go except forwards down the hard shoulder? And if it's blocked by a broken down vehicle, now you're stuck behind that, with no gap and nowhere to accelerate into.

I'm not suggesting creeping up to the point of vision but stop if there is no possibility of entering. Wait for an appropriate gap and accelerate on the hard shoulder if necessary.