RRAS Woes

I'm having so many problems with RRAS in so many scenarios I don't know where to begin. But I'll list them in order of perceived difficulty to fix:

DHCP Not Working
Okay, this isn't to do with RRAS, but the DHCP server that's also on the same box. Sometimes when I connect my laptop to my network it often fails to get a DHCP lease, I'm not sure if it's a problem with my laptop or not though. If I give my laptop a static IP address everything else then works fine. A lot of the time it works fine though. When it doesn't work disabling/enabling the adapter doesn't work, neither does hitting Repair (often it stays open and the "Close" button doesn't do anything). Only a few times when I renable DHCP on my laptop does it work, the rest of the time it just sits there "Aquiring network address..."

NAT failing when Dial-on-Demand Enabled... or disabled
This is where it gets a bit voodoo. My network has my laptop and desktop connected to a switch along with a WS2008 box. This WS2008 box has RRAS installed and functioning as a NAT router (it has two NICs: the first is to the Internet, the other to the LAN's switch).

When I go Routing and Remote Access > %server% > Properties > General and check "LAN and demand-dial routing" then the server's NAT function stops working. The server itself can communicate with the Internet, but computers using the server as a NAT (i.e. my laptop and desktop) can't reach outside the LAN.

You'd think that by checking "Local area network (LAN) routing area" back again would fix it. It doesn't. In order to get the NAT working again I need to disable RRAS and go through the configuration wizard to recreate it as a NAT and it works again.

Connected to a Remote Access VPN, but can't ping/access anything
I have an RRAS box at another site which serves as a Remote Access server, it's PPTP for simplicity (I'll change it to L2TP once I get it working properly). Anyway, I've created a VPN connection on my laptop and I can successfully connect and authenticate myself with the VPN. So far, so good.

...but I can't ping anything. I can't even ping the IP address the VPN gave me for my gateway computer, let alone any other devices in the target network. I've tried both an IP address pool and DHCP Forwarding but with no luck.

Creating a demand-dial connection to that remote-access VPN
Eventually I want to get a Site-to-Site VPN working between the two sites using the WS2008 box at my end to act as the router to the other network as well as serving as a NAT for this network. I know it's possible with static routes but I don't know what I should do. But clearly the other three issues need fixing before this can work.

Any ideas?