Ragost’s last ability will check as the end step starts to see if you gained life this turn. If you haven’t, the ability won’t trigger at all. You won’t be able to gain life during your end step in time to have the ability trigger.

If Ragost somehow becomes an artifact, Ragost will also be a Food.

If an effect refers to a Food, it means any Food artifact, not just a Food token. For example, when you activate Ragost’s second ability, you can sacrifice any Food you control to pay its cost.

You can’t sacrifice a Food to pay multiple costs. For example, you can’t sacrifice a single Food to pay the cost of its own ability and also to pay the cost of Ragost’s second ability.

The artifacts retain any types, subtypes, supertypes, and abilities they have.