You shouldn't need a consultant to open a company. Should be a form and that's it. Maybe an accountant to certify your books, but that's it.
To me things taking longer and being more complicated sounds entirely reasonable and natural in such setup...
Under some circumstances you can be held liable through a GmbH, but not generally speaking.
> rejecting the option with VAT number
Means you are planning to run a small business (making less than minimum wage on a yearly basis), also you are opting out of Vorsteuerabzug. Anyone that wants to live off their business needs VAT. And that is given by Bundeszentralamt für Steuern and the wait times are often excruciating.