I didn’t know if this was some normal twist that a wholesaler could possibly go for with the argument that I agreed to XYZ and if they got the seller down, it should be their profit..

The 8-10% management fee is normal for PM. depending on how long you lease and the state that you are in would be the biggest factor.

Also...in example, spending $20 to put your logo on a pair of $60 pants - even if you get the tax deduction, you likely would have had more money in your pocket to just wear normal pants without a logo.As noted - clothing should not be suitable for everyday wear in order to be a tax deduction. 

Since I am a newbie to this, I am curious as to how normal this situation is, with value-add properties and putting money into the property.

You pay as if it's a normal investment property, like a LTR.

Normally the easiest and the least amount of documentation. 

Lastly, your lease will look more or less the same as normal but you need to name the address and unit number (ie 123 Main st, bedroom 1) and you need to define a common area.

As everyone has stated, HML are normally for business purposes.

We have a normal REI business with this 4-plex on the side and it takes some juggling. 

When you talk about the travel nurse aspect, yes they normally travel in pairs but I think they will want more space than what you can provide.