Construction service description received - your experiences with it?

I have been dealing with the topic of construction for some time now, have bought various books, and am diligently reading along here. With every conversation at a construction company, I learn more; sometimes I realize that I hadn’t thought about certain things that way, or that the consultants have varying levels of competence and sometimes tell exactly the opposite of what their own homepage or their competitor or colleagues provide as information.

Since I am aware that both my own still amateurish ignorance could end up costing me dearly later and also that the incompetence of the sales representatives/developers will ultimately be more to my detriment than theirs, I naturally want to protect myself.

What basically works is that I present the competitors with each other’s offers, as they often, in an attempt to discredit the competitor, point out many possible weaknesses, although as a layperson I cannot always judge what is actually a problem and what is just hot air. After a longer selection process, if I have 2-3 favorites, I would like to give the offers with the description of construction services to an expert. Whom should I reasonably ask?

a) A local architect (who might again work with the local solid construction companies)
b) A building surveyor
c) A civil engineer
d) Additionally the construction department of my bank (which might also have construction company X as a client)
e) Additionally a construction law lawyer who reviews the final contracts

What would you suggest?

Points b) and e) I have done, it was worth it. Although only part of what the specialist lawyer recommends is included in the contract for work, it’s better than nothing. I even joined the Bauherren-Schutzbund and am now spending about 1% of the construction sum on construction supervision. Since we are not on site, I found that sensible.