Is "我爱辣" (Wǒ ài là) a correct/understandable/idiomatic way of saying I like my food spicy?
This happens when the food can be cooked with (little or much) or without spicy. People ask how should the food cook for you, 我爱辣 (a weird expression) answers this question indirectly -- I like spicy so please put a lot of it in the food. The direct answers could be:


不要 (bùyào) / 不要辣 (bùyào là) / 不放辣椒 (bù fàng làjiāo) "cook without spicy"
微辣 (wēi là) / 少放点 (shǎo fàng diǎn) / 一点点 (yī diǎndiǎn) "cook with a little spicy"
要 (yào) / 多放点 (duō fàng diǎn) "cook with a lot of spicy"


要 (yào) should mean default spiciness and be enough for most people. 多放点 (duō fàng diǎn) is for those who really enjoy spicy.