Learn English – Could you wish him a [get well soon] for me

There is nothing wrong using

Could you please get him for me

Commonly one would say

Could you get him, please (as you motion towards the person you want)

There will also be situations when nothing is said and only gesturing occurs. For example, during an athletic event when noise levels are elevated.

The formulation you quoted is not clear - the problem is not in the grammar of if, but in the misused vocab. Your formulation where you explained what you meant:

since the question is simple enough I wish to get answered as quickly as possible

while rather blunt and not exactly polite is far easier to understand.

It is not really a matter of language, but I don't think that there is a polite way to say: This is an easy question, so the answer should not take too long. The first part makes it impolite, because you are assuming what is easy/difficult for the person who has to answer and what's more that they should make your question a priority.

To be polite you can omit the first part and nicely ask for a quick response. For example:

I would really appreciate a quick (an urgent) response.

Another way is to state that you are in a hurry for some reason (specified or unspecified) a for example:

This matter is urgent for me (because...), can you please respond quickly?

Don't forget that a thank you goes a long way.

You might also find these options from Merriam-Webster useful.