I don't agree with all of what you say here, however points 1&2 are reasonable ideas, regardless of a terrorists religious affiliation.Ah the good old Britania at fault for the world's problems line. No wonder Europe is in the dire straits that it is when we've gone along with this false assumption for so long.
Effectively you can't stop this in a modern liberal society, stopping this completely would be to effectively outlaw Islam and it's practise/literature in the country and a ban on migrants from Middle Eastern countries. Effectively Islam would die out over the generations.
In reality in our society the best we could do I would imagine is:
1. Anyone on the suspected terror list or who has links to extremism to be deported or apprehended before it goes too far.
2. Put these Muslim prison gangs in isolation units to stop the radicalisation going on that's rife in our prison system.
3. Initiate some form of compulsory cultural integration programmes with the Muslim communities in the likes of Luton, Bradford etc. Which is difficult and I don't know how it could be done but their needs to be more integration so these fundamental issues are not allowed to fester in those vulnerable to be radicalised.
I believe it's a terrorism/extremism problem as opposed to a purely religious one.
The terrorists use religion as an excuse to be violent monsters.