It is noted in the description of the things you produce if you need a talent or not.
So for strongholds, you can see that for a garden you do not need to be a builder (REQUIREMENT: —), but for a guard tower you need it (REQUIREMENT: The BUILDER talent).
The end of the book further specifies things you produce and if you need a talent or not. Like for a Canoe, you don't need to be a builder. But to build a Rowing Boat, you need both Sailor and Builder.
For lockpicking, nothing in the talent says that you need it. The talent doesn't say so, and the rolls just get a modifier.
For chef, well it is at least needed to make "field rations", i.e. food that lasts for a week and that can be carried around. Everyone can just eat meat and vegatables, the rules are a bit vague if you just eat them raw, I think you can? There is no bonus for roosting it over a fire if you are not a Chef.
(if you want a house rule, maybe let anyone make food, if they (just like a chef) spends 1QD making it, but unlike a chef, make this food spoil if it is not eaten within a day?)