Or is it just the 7 deadly sins. And why seven is so important?
The seven cardinal and contrary virtues.
Yes, it’s from an atheist site, but the description is accurate, AFAIK, as well as nicely concise.
Seven was a mystic number throughout ancient cultures.
Also, the The Seven Deadly Virtues, sung by Mordred in “Camalot.”
Why are abstinence and chastity considered different virtues?
Well, there’s Galations 5:22-23
One can be abstinent from things other than sex.
Also, chastity does not mean abstaining from sex. A chaste person, under the ecclesiastical definition, has sex only as appropriate, i.e., within marriage.
How about the beatitudes?