I do understand the reasons for defending one's own project. That is somehow normal and quite honorable. And yes, the responding comments are rather not encouraging, but instead evoke a certain uncertainty that one really does not want to have.
Critical, pessimistic, and enlightening comments should not deter from the project, but only serve as a kind of incentive to address these points in one’s own interest. What remains can be a clarification / explanation / contractual agreement that excludes the risks raised (as well as possible) or leads to you accepting these risks (fully aware of their possible extent) as "bearable" for yourself. Sometimes, a warning about possible significant cost increases (e.g., problems with soil / water, etc.) results in the desired project ultimately proving to be unfeasible and requiring a different plan, which may also culminate in starting a new property search.
And yes, I also sometimes think that (e.g., with financing contributions) things are painted in a very dark light. On the other hand, one can and may carry out the project despite knowing the comments. In that case, the decision is made consciously and with awareness of the possibly arising problems. Not all financial concerns materialize into actual problems.
In your specific case, however, you might (albeit laughingly) be running straight into a circular saw. It is all quite vague and un concrete. That regularly means that the actual executions are rather on the lower end of the cost spectrum and may not deliver what you envisioned. That then means additional costs for changes, which really hit hard because the developers (quite often) then crank up the prices significantly (you have no choice regarding who has to carry out the work, price comparisons are possible but the negotiating leverage is completely lacking).
As I said, I am keeping all available fingers crossed, although ultimately it does not really matter.