Welcome to the list Steve!
1)Opinions differ but I use only the vw coolant the added cost is worth the
peace of mind to me.

2) The Bentley manual has allowed me to keep my 83 w/c running on a shoe
string budget and I highly recommend it. At a $100 dollars it's not cheap,
but that's not even 2 hours shop time.

3) I've been using the k&N filter for about a 8 months now and have been
quite pleased with it. I just washed and re-oiled it last weekend, a bit
time consuming but very simple. In the long run it will pay for itself.
Longevity coupled with the alleged improved flow make it a good purchase.

Good luck and happy motoring, Jim