Some Rookie Questions

hey guys i'm thinking of getting PSU episode 1 for christmas and i had a few questions before hand, some about episode 1, some about episode 2.

first and foremost: what is the limit to the number of photon artes, bullets and technics a player can know? and is there a way to forget the learned skills?

second: is there any benefit to leveling up the Ranger and Force types in episode 1 and 2? or can i just stick with the hunter (i saw information about advanced classes on the internet but i'm not sure if you can use them in the offline modes)

third: what will carry over if you transfer your extra mode character from episode 1 into episode 2

fourth: are there any bonuses other than having Karen's partner card for transfering data?

fifth and final: i read in the faqs on gamefaqs that there are certain areas of the story missions where you can return to the cities, causing certain areas of the mission to respawn their enemies allowing for additional item hunting (i know there's one in chapter 2 during ethan's first official mission in block A of the Raffon Meadow, and having read the walkthru i can assume that there's one in Block A of the Mizuraki Conservation District in chapter 5)