"Busy" means one of two things:
the daemon has not finished syncing the blockchain
the daemon has not found at least one other peer
Run "status" in monerod, and it'll tell you about both these things:
The X/Y numbers at the start of the line tells you the height it's reached vs the height it thinks the network reached. It'll download ...
Is there any other build options that compiles monerod free of runtime exceptions and better optimized for x86-64?
The exception logs did used to be a bit spammy until the latest release (v0.17.2.0) and almost all of them were one particular issue that had no material impact. If you don't want any logs just launch it with: --log-level 0. Using any build ...