Do it right the first time and you will save yourself a lot of grief later. Ripping all my masonite into one inch strips was challenging enough and I had the right equipment. Much thinner than an inch and you will run into big flex problems as you build your empire. Same goes for number of splines used.
I am not sure why you would want to put cork on top of the spline as you can bevel the edges of the spline and save some money on cork. Run your scenery up to the edge and use various fillers to fill any gaps. I also used a rasp and some small levels to put built in super elevation into the spline and was very pleased with how it turned out.
This is my first layout that was built to be permanent after returning to the hobby after years away and I followed the advice of these forum members very closely every step of the way and have had no frustrations or setbacks at all. Here is a photo of my very first layout using spline. The track is now laid and I couldn't be happier. Good luck with whatever you do and keep us posted on your progress.
Brent
