I had a Daewoo Matiz for just over a year and had similar problems with very poor handling and zero grip - not fun on the steep, wet, cobbled streets of Edinburgh centre.
Honest John review seems to confirm the handling issues with the Charade - puts it down to narrow tyres.
After coming from a Peugeot or a Citroen you aren't likely to be able to match those for handling and ride in most other small cars. I suspect lowering will just affect the ride quality with only a marginal benefit. Another aspevct is the narrow track which means that you rock from side to side a lot more than in a wider car, and the short wheelbase makes pitching a lot worse than it could be.
The original Mini was only 10ft long and my namesake (<--- him in the photo) got someone to make an interlinked front and rear suspension to try and mitigate the effect.