(by attached, it doesn't mean anchored to the ground or on a foundation, it's a paperwork/legal thing that has to do with how it's titled.)I've looked at a number of mobiles (mostly doublewides) but never purchased one.

This will give you the ability to hit the ground running from Day 1 being involved with transactions, how they work, etc. 

I am currently in the learning and researching phase.

My partners and I are discussing placing an offer on a duplex that has an in-ground pool fenced in on one side of the property.

I'm not fan either, but to be fair I was able to re-rent many of those nights at a discount, bringing my revenue to about 90% of what it would have been without the cancellations.I wish Airbnb found more of a middle ground when deciding what they were going to do.

I just built 2 townhouses from the ground up and it was WAY harder than any remodel I have done. 

How long different phases of construction will take so you know who to schedule when?

I'm currently on a deployment and really want to hit the ground running when I go home with my VA Home Loan in purchasing a multi family property.

I'd say case by case which is more tedious, roofs vary in length of life from leaf litter, to heat exposure, to freeze thaw cycle to if they were maintained by the previous owner, most of the time you can tell if a roof is in good shape, iffy shape or bad shape from the ground. 

The key is to focus on only a few places where you already have "boots on the ground."