I would recommend you to start with checking out this thread is you didn’t already:
https://forum.treeofsavior.com/t/guide-mage-builds-general-discussion/125788
It does have some nice build suggestions and analysis of different classes.
As of the build you’re suggesting - in terms of classes pyro works fine with linker although the class choice kinda depends on your play style - if you plan on playing solo or with a company.
About the skills - personally I wouldn’t level Earthquake to 5 as imo it is a waste of points if you take linker. This skill knocks up your enemies and pushes them away from you, which often breaks the link because of the distance. I would leave Earthquake on 1 for the utility if needed, and put the remaining points into Sleep. It’s not very important, but just a suggestion.
Also for a pyro I would put at least one point into Enchant Fire especially if you plan on using rod + dagger. If I remember correctly from cbt2, the dagger will add damage once to your main attack + damage to the Fire property part of attack from Enchant fire, unless they changed something. I didn’t play on kobt, so please correct me if I’m wrong here :<