Master vs Mister
Would it be grammatical and idiomatic to use master instead of mister or would people think I am mocking them and therefore I am disrespectful? I have no problem sounding Oxonian or being verbose but I would certainly dislike being disrespectful and mocking.
I am not confortable using mister, sir or lord.
My problem with mister is that I think of being a mister as less than being a master.
My problem with sir is that etymologically it means senior, elder. From Senex.
My problem with lord is that I fear that using it would be mockery more than using master.
Greeks call Κύριε every person they do not feel confortable enough (T-V distinction) as well as God even though God is treated as Tu not Vous.
In the Romance languages they are more fond of using Senior derived words and not Dominus derived ones but it is not a problem calling people Dono/Dona instead of Senhor/Senhora.
I suspect most people would be confused. Others might even be offended, associating the address Master with slavery.
In English, the honorific "Master" has an archaic (out-of-use but still familiar) use for addressing young boys, who are not yet in such state as they can properly be called "Mister". I am not aware of any other still-familiar, general-purpose use of "Master" as a form of address, though narrow uses exist, for example of someone's martial arts trainer in some practices, or in the context of African-American chattel slavery.
My problem with sir is that etymologically it means senior, elder. From Senex.
The etymology is irrelevant. "Master" and "Mister", for example, derive from the same root, yet you treat them differently, as rightly you should. Etymology and meaning are not the same thing.
The English equivalent of the T–V distinction is when you refer to someone as Mr Smith or Mrs Jones because you are not on a first-name basis with them. You would also use sir or ma’am respectively for those two individuals.
Mr Smith, your car is ready for you now, sir.
Mrs Jones, your car is ready for you now, ma’am.
Those are two separate markers, but they go together as a form of distancing. Anything beyond using sir or ma’am with people you are not on a first-name basis with, like our Mr Smith or Mrs Jones, is just going to confuse people — at best, and offend them at worst.
Avoid at all possible costs calling people you even don’t know by strange names. They will take it as a form of unlooked-for hostility.
There are virtually no situations in the UK where you should address anyone as "Master" or "Lord". As has been said, to do so would cause confusion or offence (to the extent that, if you were in a bar, you might well get punched). Even as the address for a young boy Master is very old fashioned (think of an elderly relative sending a birthday card).
The only occassions where these terms are used are extremely formal - to the extent that the person so addressed is likely to be wearing ceremonial clothing.
I have students from outside of the UK who are uncomfortable addressing their (university) teachers informally. It is fine for them to use "sir" when they speak to me. The equivalent for a woman would be "ma'am". I am nearly 60 and I suspect some of my younger colleagues find it a bit strange (though acceptable) to be addressed like this. Mr or Dr Smith, Mrs/Ms or Dr Jones are always fine, as is Professor Singh. You won't hear many other titles commonly used.