the mk4 chassis is rubbish for handling anyway even if you do all of the above but the 1.8t engine is immense for tuning.
completely agree with that
I have to disagree, I have done all of the above - The above list is in actual fact my suspension setup, I don't know what suspension modifications you have to be fit to say so definitively the handling on my mk4 is "rubbish" however having owned an ep3 I am able to make a good comparison with what many consider to be a good benchmark. So while it isn't the greatest handling fwd or particularly good value to modify the mk4 chassis, I will say that it has got potential.
I just think handling and braking is more important, I am aware a large majority are more inclined to slam and make their golf 'scene' and 'sick' over handling, which I find not least ironic that they should see themself fit to give advise on handling.
I would also throw this out there for people to consider:
2jz stock engine capable of 600bhp
K20 (type r engine) stock engine capable of 500bhp
Sr20 (Nissan primera gt) stock engine capable of over 400bhp
1.8t stock capable of 300bhp/ft-lb immense?

I like VAG but I would not say that the: "1.8t is immense for tuning" in fear that I would come across as naive, there are a number of engines that are truly deserving of being called immense. If I'm honest, the 1.8t engine is no more immense for tuning that it's chassis.