Talk to other hosts in the area, join facebook groups and ask them what obstacles they faced as well.

I'm planning to build a detached ADU.

New build detached with purpose built legal suites start close to $700K and up. 

I also wanted to pick everyone's brain if they think multigenerational living will become the new normal driving up the need for attached and detached secondarily living quarters.

Will the land allow you to build a detached unit, or otherwise on the property that will give you greater cash flow.

It has to be near enough to my job, safe enough to live, and I'd be looking for something with a detached garage or shed able to be made into a studio apartment.

2.Iv'e been hearing a lot of sentences like "you have to look at 50-100 houses before you buy" and "only if you are looking inside the house you can eventually estimate the real value" and so forth. now, this sentences are very logical and seems true, but as for now i am not in the position to do that sort of stuff. i have to trust indise guys that will help me, and to be totaly dependent of them. and advise how can i overcome this obstacle?

I recently was told that a semi-detached can be rented 1800$/month.

ADUs can be attached or detached, and up to 1,200 SF.

Their average cost estimates were $250/sq foot for a single-story detached or attached ADU.