What made my investor interested in this deal was the location, condition, and the good rent as is.

Regarding the walkthrough you should have something that documents the condition of the property when they occupied the unit.

The house was built in 1993 and is in good condition in a good area (B neighbourhood).

what condition?

The inspector will notice the condition of the home when he is out for rough inspections; what will he/she say when they come back for final inspections and notice a fully rehabbed house?? 

I'm now thinking about trialing a smart vent (register) for the super over conditioned room. 

My property is all in fairly good condition so there’s not been too many headaches.

The property is a SFR in a good neighborhood and in excellent condition.

We have had some very wet weather here and I have discovered a bit of water on the 3rd floor unit sheetrock, and some water at the wall level (same spot on the building) of the 1st floor unit resulting in some damp sheetrock.

If it’s a flip, I could reason the cost.If the entire house is 103V, its an internally shorted main breaker (cheap), an issue on the power companies end (free), or a shorted common from the weather-head to the main (not rewiring the whole house).