i read a quote that said (basically) "it is not illegal to
misrepresent yourself in business"

however, i'm confused and seek clarification and where possible,
citations and references to legal discussion or other relevant and
reliable discussion.

i already know that it is legal to generate a "DBA" (doing business
as) name for a business where "inc" or "corp" aren't used, this is
common (e.g. xyz manufacturing inc. doing business as "supercheap
stereos")...and i already know that it is legal for a company to, for
example, register at a hotel under a fake firm name to conceal
(hypothetically) secret merger talks and so on...

and of course many authors take pen names...and many celebrities
incorporate their own names and then take other names in acting and so
on...

what i am specifically interested in is the use of personal and
company aliases in business.

sample questions to steer you: 
what are the legal definitions and constraints of "fictitious names"
for use in business research?
if i am jim jones from company x, inc. and present myself as "jack
james from company z" (no 'inc'), and my goal is to obtain information
through dialogue with an employee of a company under this assumed
name, at exactly what point has the line been crossed - if at all?

i'm not interested in the ethics, that's already understood. i'm
interested in the legal aspects. if there is great variation by state,
or for example, the state from which the communication originates,
please indicate such info.

if you need further clarification, please post.