I grow indoors. peppers, herbs, strawberries, tomatoes and cucumbers. snails might not get in, but once you get mites, and whiteflies and stinging gnats, its pretty much a constant struggle and a tradeoff between using really aggressive insecticides and chasing down infected plants. mites have been the worst, managed to stomp out the whiteflies and the gnats though.

Ideally I automate that part as well, with HD image processing and finding the source and either alerting me to do something or do it on their own (it probably will be a while, till I get to that level).

with the mites, unless its a leaf that shows the bite marks very clearly, you really need to move the leaf and look underneath. actually even if the bite marks show, they mites are pretty clever, they like to live in little turned under sections so you really need to flatten it out and get in there. ideally you'd look for eggs which are pretty damn small. many plants will also self-interfere (tomatoes), so you get little tangles of leaves that provide great hidden living spaces for them.