If you are just getting started, good insurance may be the better play.Assuming you have a large portfolio, you know how to manage an LLC properly, are willing to take on the added paperwork and expense, and are not piercing the corporate veil by having mortgages in your name, here are my reactions to your proposals. 

Probably best to look elsewhere accordingly, as the availability of properly zoned STRs is quite limited.   

Loan balance is 280k, value is over 500k, cash flows about $1300…went to apply for a business line of credit thru my operating LLC and was denied due to losses in last years schedule E…the idea was that I use the LOC to help pay for a down payment.

Are they good with tenant and vendor followup to ensure job has been done and properly?

@Tyler Condon, it isn't proper but people do make side deals where the parties exchange money separate of the closing but at the closing table.

The other thing I often see is that over time, different homeowners/contractors have decided to DYI adjustments to their home aka took out walls, didn't shore things up properly, put in new doors, etc.My point is that what you are seeing is not abnormal for older homes. 

:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

., smoke detectors, proper handrails).

As long as its renovated PROPERLY and tenants are screened all should be good. 

It's hard getting to the door knocking while trying to balance my military job, family time, and upkeeping my own house.