How soon do I need to involve the lender in this process?

I wish they all could say "NO" if they really didn't want to do the job, instead of wasting time for both of us involved. 

In my opinion, a 'complete renovation' would normally cost more then 10K per unit but then it depends on what they mean by 'complete'.There are lots of questions to ask and have answered before you can determine to move forward of not;- Statement of work (SOW) regarding work done- What is warrantied and for how longetc.Also while this is not a 'turnkey' as it seems that HW does not own the property, they are certainly intimately involved.

Heloc is your best bet as an investor.

There is a variety of ways to invest your money, real estate by far to me is the safest bet and Oh the tax write offs should be more than a good motivation by itself.  

With your background in construction why not get a cash investor or hard money lender involved and take down the deal yourself?

Personally, this is where I would get a GC involved.

I do not believe race is in any way involved, however this information helps to explain why there has been a lack of direct communication between myself and the other tenants.In the ten years I have lived here there haven't been any arguments, disputes, or angry interactions with anyone here.

I’m very excited to be getting involved with the community.

This article talks in detail on how to evict a tenant plus the associated costs (and headaches involved): How to Evict a Tenant for Non-Payment of Rent (includes costs) .