How long can an Etsy title be?

Where each part of the title goes
PositionContent
Characters 1-50Primary buyer keyword (product + main attribute)
Characters 50-100Secondary keywords: style, material, colour
Characters 100-140Occasion, recipient, personalisation

Does a longer Etsy title rank better?

Not by itself. Length only helps when the extra words are real search phrases buyers type. A stuffed 140-character title of disconnected keywords reads badly and lowers the click-through rate that Etsy measures.

Should the shop name be in the title?

Only at the end, and only if the brand is already searched by name. The opening characters are the most valuable ranking and click space on the listing.