Since every lender has their own way of underwriting a file (global cash flow, creditworthiness, etc.) you generally want to disclose the proper amount and only more if it is requested.

For example, are these relationships built in the creditworthiness of the borrower, the analysis of the flip, etc.? 

If they have no credit lines, but have legal status to reside in the USA, then your policy on creditworthiness will determine whether you accept or reject.

If your net worth can cover the debt and be secured, credit will be less of an issue.Any smallish company will always be required by any institutional lender or an private lender that has any awareness, to provide a personal guarantee and that individual's personal credit will be not only taken into consideration but the primary credit determination, not past entity credit lines under previous owners.A new owner does not inherit the credit worthiness of past owners as these credit company scams claim.

@Matt GeertsIf your banker is telling you they would consider cash in your account to be "seasoned" after 31 days, s/he is also telling you their diligence is a little light or they are willing to "not notice" certain things in the interests of underwriting a mortgage.If the LoC is longstanding (i.e. the 90-days Luc mentioned above) then it will be factored into your credit worthiness and DTI and still have an impact on your ability to borrow.  

LTVs can be high depending on sponsor experience and background, project attractiveness but is not based on individual creditworthiness.

Responsible, credit worthy people don't want to do that.Yes, tax returns and bank statements showing consistent income for self-employed.Go vacant instead of getting in bed with a tenant that is going to make your life hell.

(not endorsing them but can cite their merits) It enables a Landlord to get a just & fair snapshot of the creditworthiness of a potential tenant.

Hello friends, How do you verify creditworthiness/reliability when renting to foreigners?

Commercial rates are usually a little bit higher then residential rates but you sound credit worthy so I don't think you would have to worry about subprime rates.