Is it OK to remove a registry? Will it mess up with other things?
Yes, it should be OK to remove “JuliaPro” registry and it should not mess up your installation. Based on your logs, your JuliaPro installation had 3 registries
JuliaPro
JuliaComputingRegistry
General
Packages will be pulled from JuliaComputingRegistry and General registries once JuliaPro registry is removed.