Yes you can use the original gaskets but I wouldn't, 99% of the time some of the gaskets stays on either side of the covers and once soaked in oil as they will be , they no longer seal 100%. For the small price it costs to buy new, I always buy new, even on my bike that comes apart every year at least once.
Yes the only way to drain the forks on the newer version bikes is to tip them upside down....however you choose to do that....lol...but as stated before remove forks from bike first....lol.
I have thought that there is still the boss to be able to drill and tap a hole to do the same thing as the older versions have once you get the forks off in the firstplace. Look very closely and decide for yourself. I haven't done one yet but it does look like it's possible. If it doesn't work you could always thread and plug the hole up. If I had an 08 I would be having a go at it for sure rather than taking the forks off ever time. Stupid Kawi again!!!