Most of the time the categorization is simple enough and I can do myself. 

Do your due diligence upfront on the person (simple google search with their name and lawsuit or scam can weed out many - as well as a search on BP)2.

Do it yourself is almost never recommended, although I’ve done some simple deed transfers myself.  

We did a 100% gut/rehab on a 1950's house in 2018 and converted it to a duplex, turned out beautiful, salvaged the original wood floors in parts of the house, put good LVP in the rest, simple plastic mini blinds on every window.

Closing fees won't be any different if they are 4 seperate fee simple properties.

I am a real estate wholesaler operating for the past 4 years in the DFW Metroplex and I found that it's better to keep things simple, and not, deal with real estate agents who don't want you biting off (what they view as) their profits.

When I was active, the O-4 Good Idea Fairies always tried to re-invent how we did business, and 95% of the time, they overcomplicated a simple process making our lives way harder.

For estimating rehab costs, I can send you a simple calculator if you’d like.

You can usually find some events by doing a simple google search.

A good starting point would be a 10% 2nd home loan or an owner occupied 5% loan where you can convert a basement or studio into a simple 1 bedroom unit and basically let your guests pay your mortgage.