It could go on depending on your point view, and i'm someone will inject accounting principals...

For fentanyl contamination; understand that the folks who are overdosing on fentanyl (which is very powerful, as you mentioned) are generally injecting it directly into a vein.

Likewise, you cannot inject value into the IRA via the provision of goods or services above and beyond basic administration.  

You are buying to inject capital into the property to hopefully increase rents and therefore value.

You've injected capital to improve and repair the building and want to bring rents to market levels to make a return on your investment.

Any cement previously drilled through where a termite company injected their chemical and patched the concrete?

When I look at a property, if the numbers don't quite work, I ask myself, Can I do something to inject some value to the property and increase the income and/or value of the property? 

On paper it seems like a good move to get an injection of cash that we could use to pay down some debt on either this rental or primary.- Any other comments/suggestions so that nothing gets weird with my Dad?

Spiders have fangs that inject venom into their prey, and most kinds spin webs in which to capture other insects." 

But if no slab leaks are present then I believe I would just rent it out and fix the crack later with foam injection.