Do I owe an expiatory offering for an oath (kaffarat yameen) because I bought an e-cigarette, asked colleagues for it, and smoked shisha and e-cigarettes, after previous oaths not to return to smoking or buying cigarettes?

The e-cigarette does not differ from the traditional one in terms of ruling. If you swore to quit traditional cigarettes, and then consumed e-cigarettes or shisha, it appears that you have broken your oath, unless your intention in the oath was only traditional cigarettes. Assuming the oath is broken, a single expiation is required, because the intention is to abstain from consumption in general.