Questions about 'would'

[Xiaoape]

For example, if the programmer tells the computer “take over the world” and it wasn’t designed to be able to take over the world, then the computer would need a new “take over the world” feature. That wouldn’t be a bug.

In the above sentence, why does it use "would"? Can I use other modal verbs? Is it "would" in the form of past simple?

What about these two examples below:

Anything that involves the overall design of the system or the technical decisions you make while creating the system would fall under this category

Technical decisions would be things like: “Do we go with a..."

[Dozy]

In the first example, "would" is describing hypothetical events occurring in a hypothetical situation introduced by "if". It's just like "If I won the lottery, I would have my own private jet." It has no past tense sense here. As far as other modal verbs are concerned, it is possible, with a slightly different nuance, to use "might" in that sentence.

The second and third sentences are examples of weakly hypothetical situations. You can interpret as:

"Anything that involves the overall design of the system or the technical decisions you make while creating the system would, if it happened/occurred, fall under this category"

Technical decisions would, if they happened/occurred, be things like: “Do we go with a..."

However, in such cases "would" verges towards simply being a "softening" word that makes the sentence seem less direct. You could say "falls under this category" and "are things like" without a great change in actual meaning.