I heard that it will be nearly impossible to get traditional financing with an LLC, is this accurate?

Also that lot isn't "on" lake Minnetonka, I mention this in case you think it is...Few concerns I have are as follows:-I don't think you will be able to get traditional financing. 

However, it sounds like I need to just go the traditional 30 day eviction route. 

E.g. owner is being foreclosed on, you come along with little to no money available to buy the house from him traditionally so you offer to buy the distressed owner's house subject to his existing mortgage. 

My places are very busy and my monthly income is greater than 3x what I'd get if they were traditional long-term rentals.

Depending upon what you find, and other factors, it might be cheaper and easier to just replace the slab area with a traditional wood floor joist system and plywood.

To refinance into a traditional mortgage you will most likely need 12 months of seasoning on the rents being generated. 

I have a full-time job and my employer offers traditional 401k.

Traditional "wood" laminate works well on reasonably uneven floors, and it's easier to install and generally looks better than click vinyl plank.

That said, I can't speak for other brokerages but I can say I started out at a ""big box" traditional firm and they did not understand my investment business AT ALL.