Furnished rentals are currently renting for a premium to people relocating here and remote workers, and that’s the best way to achieve cash flow in the Boulder market IMO.

Seems that a MIL suite would attract buyers looking for a space that they could either AirBnB/VRBO, house-hack (off the books, roommate-style), or put a genuine in-law into, depending on what stage of life your buyers are in.

Appraisers are supposed to look at location, configuration, size, condition, style and then after all of that is done, then they can get super picky with aspects pertaining to lot location, lot size, or uniqueness of the property or whatnot, such as the floor plan.

Definitely check out a meet-up, you will surely meet some interesting personalities and will no doubt gravitate toward someone with a similar style to your own. 

The old style couch makes it look dated.

I am interested in multi-family to achieve this, but open to other suggestions if there are better options.So my questions are: 1) What books/podcasts/webinars/authors/resources would you recommend to get me going again? 

I don't trust a group that has 500 doors to be as efficient at property management as a group with 5,000 doors.Biased to value and long term appreciation, as long as the plan to achieve it seems sound.  

The price someone will pay ultimately matters.You're going to get a lot of opinions with this question and all that really matters is what you and your brother-in-law want to achieve.

So, we are NOT house hacking, we are NOT going to do the equity rollover to each new property, and our plan is to use our fairly large income sources to buy turn-key income-generating properties for long-hold to increase overall wealth in our investment portfolio.I really look forward to getting some more learning in about how to best achieve our goals!

Your likelihood of success depends a) you learning about the best practices for whichever area(s) of REI you choose to pursue, b) taking action on what you learn, c) not giving up when you face challenges, and d) building a network of people whose expertise, skills, and resources you can leverage to achieve your mutual goals (realtors, lenders, other investors, CPA, attorneys, etc.)Best wishes in your future plans.