This is true regardless of how long you have owned a vacation rental. 

The offer to “help” hopeful participants obtain increases in their credit card limits6.

Be prepared to show a lease, some utility bill, or credit card statement showing you live somewhere else.

This is true for bonus depreciation items as well.  

Stay true to the niche you’re currently focused on until you start to master it.

This isn't true. there are lenders that do 80% cash out refinances - DSCR isn't the only loan type you can close in an LLC to get 80% cash out...and there are many lenders where investors can get 0% origination fees --- keyword here is "lenders", not brokers.

I think you’d be better off getting a true appraisal.

Or enter "for repairs" and take photographs of expensive new stuff for court...but they may be paying down credit cards.

Tell party #1 that you have others wanting it, which is true. 

If this were true, then tell me, what exactly are the characteristics to be motivated?