>>649119
>4) There are many saints for specific purpose like warfare, learning, farming etc (or so I have learned from EUIV)
Church prescribe particular saints as patrons of particular things for two reasons. First is that saint patron of x had connection with x during his life so it's natural that he certain graces from God when it comes to such things. For exemple Saint Andrew Bobola was great Patriot so he is patron saint of Poland. Or saint Nicolas gave secretlly money to young girls so that they wouldn't have to become prostitues so he is patron siant of prostitutes (i.e. those who been one and repented or are on thier way to repentance). Second is that people who pray may have stronger devotion to saints that were in simmilar situations. For exmple it's logical that soliders would pray to the siant who was solider like Prince of Heavenly Host Archangel Michael or great and heroic warrior like Ignatius Layola.
> How does that differ from pagan pantheons?
I could be smug and say that saints are actual gods (theosis and stuff) while pagan gods are all demons or idols but to be less vague - gods of pagans had authority over elements of themselves plus they were man-made lies or forfathers and heroes of nations that were deifieded in colecctive memory (for exemple it is common theory that in ideoeuropean pantheons three god-brothers like Zeus, Poseidon and Hades are just fairy tales about Japhet, Shem and Ham), while saints were real people whose authority comes by grace of God alone.
>>649121
>Or rather how does one approach specific saint
Fastest and easiest way is just say "Saint X pray for me". There are certain prayers to certain saints like Loreto Litany but wording is not (as) important but intention is.
>and why does it matter what they specialized in life?
See above