I just want to get the permit and go from there honestly. Isn't that what you're supposed to do? Of course the metal building people want you to buy a building. The sales guy is already like what makes you think they won't permit this building? I'm thinking to myself really???
The issue you're encountering is that metal buildings are engineered systems. There's the red iron "I-beam" style, there are ones made out of square tubing sections, there's the quonset hut type, one's made up out of back to back C-channel.
There's a lot more variables compared to stick built or pole barn which most building codes have pretty standard design and construction guidelines for. So of course, the permit office wants to make sure the design has been approved by an engineer.
Yeah, there's a certain amount of trying to lock you in by making sure you pay a deposit before giving you the detail plans. But there's also a fair bit of time that goes into generating those plans.
If they're asking you the right questions such as the location and jurisdiction for your building and confirm with them that if your building plan gets rejected due to structural design, That they'll make sure the correct the deficiency. Again, site layout, setbacks, permitted heights etc. are on you to make sure you have that confirmed with your local municipality.
Also confirm the payment terms with the building supplier. If they want 100% up front. Yes, that's a red flag. 50% down + 50% before delivery, pretty common. Mine was 25% on contract signing, 50% to put the building in production - this they were flexible on and were basically waiting for me to get my permits. Final 25% was due 2 weeks before delivery