Concerning "to trade", I saw on Etymonline:
late 14c., "path, track, course of action," introduced by the Hanse merchants, from Middle Dutch or Middle Low German trade "track, course" (probably originally of a ship), cognate with Old English tredan (see tread (v.)).
Sense of "one's habitual business" (1540s) developed from the notion of "way, course, manner of life" (mid-15c.); sense of "buying and selling, exchange of commodities" is from 1550s. Meaning "act of trading" is from 1829. Trade-name is from 1821; trade-route is from 1873; trade-war is from 1899. Trade union is attested from 1831. Trade wind (1640s) has nothing to do with commerce, but preserves the obsolete sense of "in a habitual or regular course
As etymology is not really an exact science, and it's made of deductions about old forms evolutions and even, and from intuitions or suppositions, I think another possible etymology would be from the Latin tradere.
It would make more sense, as the meanings are very close, and it would seem more logical to me.
One it could be the existence of old French forms, eventually (but their absence is not an infirmation neither).
Other clues can be the old English forms.
Is there some sources or clues about this possible alternative etymology?
If it's a Latin one, I have no idea how it entered the English language, as I didn't find cognate in Romance languages for this term (But I maybe be wrong).