Are these existing known bugs or did you open a ticket on the Go bug tracker? If there are already tickets for these known bugs, you should mention the ticket number in your code review. If there aren't tickets, you should probably start by opening a ticket and then linking to your changes.
As for your feature/improvement, it's also generally best to discuss such things as an issue or on the go-dev mailing list before digging in, if only so you don't waste time working on things that may not be accepted.