does luck affect the chance of getting a t-map from a monster?

No, luck affects the category of loot you get, not tmap chance.

When you kill a monster, the luck roll is made against the amount of luck you have. If you score the luck roll, the loot on the corpse is boosted to the next level up from what the monster would normally have.

Treasure maps are random drops, I've heard 1 in 100, although only certain monsters have a chance to carry them at all. It would be nice if tmaps got a shot at luck, either to increase their chance of occurring or boosting their level

what is the best monsters and where to hunt them to get level 4, 5 and 6 maps?
other than miasmas they are always camped.

not sure its still right but when maked my t-hunter it was..

lvl 1 maps ettins and evil mages
lvl 2 maps evil mages lords
lvl 3 maps efreets, orge lords, cyclops
lvl 4 maps cyclops, meer warriors, titans, cyclops
lvl 5 maps ehteral warriors, meer warriors, titans, cyclops
lvl 6 maps acient wyrm, balroons, blood-, poisonele, titans

also have good chances to get it from sea serpents or in paragon chests (diff. lvl)

I was seeing a lot of treasure maps fighting dark guardians in doom. It's easy to manipulate how many of them spawn and they're not too tough. I can't remember what level they were though, sorry.