What packages do you have installed on the 450?
Refer to this Wiki page to know what you need:http://wiki.mikrotik.com/wiki/Manual:System/Packages
Most of enabling IPSec/PPTP are done under the PPP menu. Read the Wiki for examples for what situation that you want to duplicate and adjust for your situation.
ICMP is allowed by default on the MikroTik, you have to explicitly filter out that for it to not work. These are not like dumb Linksys routers that assume a lot of things, and keep a ton of things hidden. You are expected with a MikroTik to set up your own security and filters. Read up on the firewall and securing your router in the Wiki for examples of how to do this.
For 6 and 7:
Port forwarding and nat rules are done in /firewall nat.
For port forwarding set up what you need on chain dstnat with action dst-nat.
For other NAT settings we would need to know what you are trying to do specifically, but once again, most of the information you need is contained in the Wiki, find something similar to what you want to do and read up on that.
This is done in /ip route