No lawyers required, but....
Hi Marlon,
Yeah, none of the non-immigration or immigration categories specifically mentioned requiring an attorney but from my perspective after comparing the US immigration website (USCIS.gov) versus other countries website I would have to say I probably need an attorney just to read the damn website!
I don't know if others would agree with me but the explanations given for every immigration category is not easily understandable by the average person. Plus since there is no way to migrate on self-sponsorship, as you require a family sponsor or company, it would seem easier to just hire someone who is familiar with US law.
If you were to visit the Australian or Canadian immigration websites, both are friendly to navigate, with links to document checklists, etc. but then again both countries do allow self-sponsored Permanent Resident applications.