Is 爱 limited to people?
this is my first answer on this website.

他爱怎么想就怎么想,我才不在乎呢  = whatever he thinks/would like to think, I don't care.
In this sentence, 爱 is generally can be understanded as "would like". 
I prefer to say 我爱吃辣(I love eating spicy food) insted of 我爱辣
If you just only say 我爱辣, people may get confused when they hear this.

爱 can be used for things/hobbies etc, but a verb often followed by 爱。Examples: I love sports = 我爱运动。 I love playing basketball =我爱打篮球。 I love playing games = 我爱玩游戏。

Sometimes, you can use 爱 for pets and animals. However, I prefer to say 喜欢. Examples: 我喜欢动物。我喜欢小狗。 我喜欢小猫。