It's very likely that most if not all of your problems are QoS related. The simplest way to begin to fix these issues is with the "autoqos" command if supported by your devices. See the link below. The other links give good information regarding troubleshooting and fixing some of the specific issues you mentioned.
Introduction: The "external-out enable" command is available for
configuration under the "router ospf process" in case of the IOS-XR
operating system. This command basically enables advertisement of
intra-area routes on the device as external routes in th...
Introduction Basic configuration for netflow Scale parameters for
netflow Netflow support Architecture Packet flow for netflow Inside the
LC CPU Netflow Cache size, maintenance and memory Sample usage Cache
Size Aging Permanent cache Characteristics Which...