I wouldn't worry too much about your level of English, your post above seems passable. Architects communicate mostly by visual means, drawings and models, if you can use those effectively then that is more than half the battle.
In terms of architecture schools, Without wanting to start another row, I will say that, at the moment, UCD is probably the best; UL is rated very highly; there is also WIT and UCC, and North of the border, Queens and University of Ulster -but I don't know much about those. But if it is points you are worried about then perhaps you could look at other options like Architectural Technology. Also DIT's points are made up of a combination of LC points and DIT's own entrance exam, though I'm not sure what the breakdown is. If you are considering it you should apply anyway and do the entrance exam at least (But don't be put off if you fail the entrance exam, it's not very reliable, I know plenty of very good architects who failed it)
Its a while since I did it, but realistically you probably should be aiming a bit higher than 350-400 points. Requirements have come down across the board for architecture courses for obvious reasons but I doubt they will come down that much.