Hey there @Jacob Munson! Welcome to the forums and also welcome to Denver! Lots to unpack here, but in short, you aren't alone in taking on the strategy of house hacking with a STR/MTR, I personally do it out here (In Arvada), and have another rental that I do it as well, plus its a popular strategy amongst our clients. One of the major factors here will be the STR aspect, the MTR space is pretty secure and safe, and would work great in any of these areas, except I tent to push people as close to Downtown as possible, but you also have to pay attention to prices. As for your questions...
1) Have folks had success with STR/MTR in these suburbs and what kinds of setups (guesthouse, private basement, etc) seem to be the most in demand?
Yes, as described above. All of the different asset types work, but I would say and ADU or guesthouse will always be the most desirable, but also the most expensive and hardest to find for your purchase. Both my units and most of my clients are private basements or full homes, and they work really well, as less expensive alternatives to hotels, while getting the amenities of a home.
2) Which areas to avoid as far as STR/MTR ordinances go
As far as the areas you mentioned only Arvada will be STR friendly for primary residents and non owner occupied properties. Denver County does not allow STRs in non primary units, and Lakewood is about to allow STRs in owner occupied units. Other areas to possibly look into are Wheat ridge (owner occupied allowed, and non owner occupied is on a waitlist), unincorporated Adams county (denver zip codes but Adam's county), and Mountain view, which is unincorporated Jefferson county but Denver Zip code.
3) Any other comments or feedback that you think might be useful.
Personally, I love where you can continue STRs after you move out, as then you can double dip in the MTR and STR market. You can have STR during the high season, and MTR during the slow season but still infill vacancies with short term stays. Arvada is great area, convenient to everything and had plenty of compatabile homes in a friendly municipality.
There is a lot more to unpack, and would depend on your personal goals and situation, but feel free to reach out any time with any more questions!