Hello,
for link high utilization you can use QoS tools like providing some resources to telnet sessions with a dedicated traffic class/queue
For the debug:
you should not enable debug commands if cpu is already at 50%
use a big buffer and configure the device to log only to the buffer
example:
logging buffered 8388608
no logging console
this can help
later you can access the log buffer to see debug messages
Hope to help
Giuseppe