In my head, it would help me sleep at night knowing the plan would be to get the additional leverage off my primary residence in a shorter timeframe than over the entire term of the HELOC.  

Will it be sufficient for your growth?

If you’re concerned that today’s market is a bubble, this should shift your focus from a possible drop in prices to a possible drop in rent.As for what rent margin of error is sufficient, the historical record yields a decent enough line in the sand.

They told me that they tried to get this issue fixed when the community was still under builder's warranty, but didn't get enough votes from the community, so they just fixed it thinking it was sufficient. 

However, we were curious on undeveloped land if things like Hip Camp and private fishing hosting etc that generate income would be sufficient to purchase the land without paying capital gains from salE Of the rental house.

Would plan on waiting 6-12 months after purchase to refinance (which means my primary lender would need to carry the loan for that long), should that generally be sufficient?

If she has sufficient income and can otherwise qualify for the rental I would be tempted to go with it.

Set a deadline for their response (one week is sufficient) and if they don't respond then automatically head towards termination.The second issue is that your lease should explain what happens if they stay longer.

Would it be sufficient to point this out to potential tenants when they are touring the property?

I think the balance of your questions depends on whether you have sufficient capital to complete the rehabilitation all at once, or do you need to get the cash flow started to offset your expenses.