1. I've ridden those roads recently. They're all glorious! You don't know how lucky you are with your surface, so stop complaining!
2. Don't use the rear at speed. Ok, there are many schools of thought but the front brake is your primary stopping weapon. Never use the rear for emergency braking. Try and drop that habit ASAP.
3. You will get used to the riding position but consider adjusting your levers so your wrists are in the most comfortable position possible. You might have them bent at a dodgy angle if your levers are too high.
4. I don't know what you mean by washing wide, but it won't be slide like car understeer otherwise you'd probably be in a hedge. I suspect you're just getting used to it all. Stick at it!
5. EBC double H pads are the ones you want. With those on and callipers in good condition with new well bled fluid you'll have a lot of stopping power. I suspect you just need to iron out a few kinks in your braking system. The stock brakes were very good on my curvy.
Glad you're enjoying it chap!