What's the meaning of the first part of: 他爱怎么想就怎么想,我才不在乎呢
and
Is "我爱辣" (Wǒ ài là) a correct/understandable/idiomatic way of saying I like my food spicy?
suggest that 爱 can be used for things and abstractions, but that it may not be idiomatic.
Would it be common, sometimes, or never for pets? Other animals? Hobbies? etc.