On my opinion you should assign a guaranteed bandwidth and priority to the OpenVPN tunnels (UDP or TCP).
Suppose that VPN00 is in server mode and uses the port 1195/TCP on the central server.
You have to add on the central server the following QoS classifier rule:
ETH00 MARK tcp opt — in * out ETH00 0.0.0.0/0 -> 0.0.0.0/0 tcp spt:1195 MARK set 0x16 Outvpn00 no
and on the remote server the rule:
ETH00 MARK tcp opt — in * out ETH00 0.0.0.0/0 -> 0.0.0.0/0 tcp dpt:1195 MARK set 0x16 Outvpn00 no
where the class Outvpn00 is applied to the Internet interface (ETH00 in you case)
Note that on the central server you check the source port and on the remote the destination port.
The rules 10-14 are useless at this point.