I get the feeling (but don't know) that the practical effects of yield/give way lines, stop signs and red lights might be different on the roads here from on the roads there, so perhaps we're drawing different inferences about how road users are likely to treat them.
For example, here in Cambridge, UK, I'm not aware of any general problems with anyone's behaviour at give way lines, but cyclists going through red lights or past other blocks such as no entry signs frequently seem to exhibit poor judgement and create potentially dangerous situations. In this case, the law is also clear -- passing that red light or no entry sign is illegal -- and I'm sure the cyclists all know that. So it's not whether they understand the law that I'm calling into question, it's their judgement about how to cycle safely regardless of the legality.
If cyclists tend to exhibit different patterns of behaviour where you are, then what we're talking about might make a lot of sense in your environment. It seems most of us agree that looking at the real evidence is the only way to be sure. But over here, at least, I would worry that changing the law in this way would be seen by a large number of cyclists as condoning their current riding style, dangerous as it often is.