hi great to see you are giving the game lots of time and thought thats all it takes.
but it does also help if you have had some motorsport or simulator backround.
ive been playing racing games for ages and i also have real motorsport backround iam a mad car nut i love cars!!!
i dont really go online cause i have slow internet and a very very slow computer
so i kinda just have no choice but to drive solo and thats were i learn work on your braking, turn in points and when you are going to put the power down. also work on not coming into the corner to fast cos you will loss stability and balence but also how much speed you can carrie out of the corner and use up as much track as possible when you exit the turn run wide and power on early.
these are just some of the basics you might allready know these things but if you dont this will really help you. you seem to be doing some pretty good times though so you do have heeps of potential
if you need anymore tips and hints dont hesitate to ask i would be glad to help you