2000 Vauxhall Astra car managment, electronics and oil light coming on and car cutting out

Hi I have a 1.4 16v astra. When driving my car sometimes the car feels a bit funny and then when I slow down and put my foot on the clutch the engine electronics, managment and oil lights come on, if I take foot off the clutch they go off and the car still runs and then if I put foot on clutch again same thing happens, but if I keep foot on clutch for too long the car will cut out (which I dont even notice as the engine is quite)! Then when I switch off and try to switch on it just keeps turning over with the battery light coming on and can take several attempts to start, sometimes it will start willingly and other times I have to put the accelerator down to start it. Ive been told it could be the ECR valve but we replaced this 4yrs ago, could this really be causin this problem? Any ideas?