Not sure if you meant it that way but it appears you have the order mixed up. Are you saying you are putting down mulch FIRST, before planting?? If so, not recommended.
Also, why would you mound all trees? Is your soil that poor draining? Other than avocado and citrus, in certain yards or areas that have poor drainage/retain water, most fruit trees would not require "mounding" as you seem to be describing.
As for manure being mixed in (and I know some disagree), I would not amend the soil with manure when planting.
After planting, then apply your mulch but NOT directly against the trunks of the trees. Leave a 6"-12" buffer between the trunk and where the mulch begins (again, some will disagree with me however you don't want to smother those crown roots).
Drip irrigation...can be useful with smaller trees IF, and I reiterate IF, you have the right drip rate/duration for each type of fruit. For instance, a jaboticaba will take, and want, much more water while a papaya would take significantly less water...and most others would fall within varying degrees with this range.