"should.."/"if..."

maelstromCan the word "should" always substitute for "if" in a sentence where a hypothesized situation is involved?

No.

If you could open the door, a breeze would blow through here.

maelstromCan the word "should" always substitute for "if" in a sentence where a hypothesized situation is involved?

Almost all questions about English grammar with the word "always" can be answered "No".

CJ

"Should you decide that's disrespectful, contact the CS manager immediately."
I don't understand why the word "if" is substituted by "should" here,
what difference does that make??

maelstromShould you decide that's disrespectful, contact the CS manager immediately."I don't understand why the word "if" is substituted by "should" here.

It isn't.

maelstromwhat difference does that make?

It is standard practice to use 'should' in such advice, regulations, guidelines, etc.

maelstromShould you decide that's disrespectful, contact the CS manager immediately."I don't understand why the word "if" is substituted by "should" here.

Mister Micawber-It isn't.
what do you mean that it ISN'T? It's written right there as you can see:)

maelstromwhat do you mean that it ISN'T?

It is not substituted; the writer wrote the correct form initially.

Also I've heard people say that in random/casual conversations,
I can go ahead and assume that they're trying to look high and mighty then?:)

maelstromI can go ahead and assume that they're trying to look high and mighty then?:

Not at all! What in the language or the explanations could cause you to think that? I think you must have a very poor understanding of the terms 'formal' and 'informal'. The latter are simply not generally accepted in careful writing.