The only attraction I can see, the lien holder is guaranteed a total  minimum interest of 5%, ie. if they bid the rate down to 2%, and the lien gets paid off in a few months, the certificate holder still gets a minimum of 5%. 

It doesn't really seem to be scaring people away but rather attracting people.

Can I raise rents immediately or should I rehab to a certain degree to justify the rent increase.

You need a plan to increase the value.

I strongly recommend you increase them to 10% CapEx and 5% Repairs until to have accurate information.5.  

I am on the board of two self managed HOA's (Lakeview /Wicker Park) and need assistance dealing with two separate issues:  #1 Noise disturbance in commercial space  #2 VERY delinquent assessments by a single owner Ive attempted to engage two firms already but somehow these issues seem to not be attractive to represent. 

I'm not sure of your market, but it may be hard to attract and hold onto good tenants at that price point. 

Regarding your question, it's important to find parks you feel comfortable working in and attract the type of clientele you want to deal with.

What kind of business person needs to increase his credit score and embellish external financial strength with help of 3rd party?

There is a home for sale right across the street from what is currently the city's fleet maintenance, a large warehouse style building, not very attractive.