That will increase your cost quite a bit and might make the ROI untenable......?

I would recommend reading the book by J.Scott called "The book on estimating rehab cost" Also, network a lot and consume wholesaling-related content to give you a better picture of how it works. 

Alvara handles it at a cost but still valid point as I do it myself like many others. 

You would need an exceptional grasp on what the 1031 will cost and the amounts you’re dealing with on the replacement and relinquished properties.- REI CPA in CA

Imagine the ARV being $15M and the Cost of repairs, $200K.

Is it worth fixing up (all properties should be fixed up before moving on to another to avoid repair costs later when you have more leverage) or is it worth selling in an imperfect state for less money (and harder with a tenant).

How much does RemoteLock cost?

Are you going to self-manage or add the cost of STR Prop.

If any of you could help me determine what kind of property damage I should avoid either because it costs too much to fix or it is just too difficult/ time consuming (things like termites, gas lines needing repair, roofing, etc.).

I have bought properties by signing a lease option where I took control over the property, made the needed repairs, and then got it financed to cover my cost and what I owed.