Select non-task workorders, but include the costs of the tasks
I know you say that

I plan to use the view for multiple reports. So I've included all 265 columns in the view via select *

but given the truly absurd column count in that table, I would consider a select-splat to be a very last resort. Are you able to narrow this at all?
Generally your query seems sane. Since you say that the following columns are non-nullable,
sum(actlabcost) + sum(actmatcost) + sum(actservcost) + sum(acttoolcost)

should be equivalent to
sum(actlabcost + actmatcost + actservcost + acttoolcost)