I thinked some ideas for the 5 job.
When i was looking in the old photos of maple( i played Brazil Maple Story), and i saw when we needed to get the skills for 4 job(i liked it), so i thinked we would need to get some 5 job skills with quests, not like get all of em at once; i thinked we could use some or maybe all the same quests that we needed to do, like the ''Protect Tylus''
Some could be get in the GPQ, like the old times; but since the ergoth got a really low life for peoples, they could increase it's life in a diferent mode(GPQ have other mode that ergoth have more life but you can get 5 job books in the end).
You could also some books lv20 and 30 there.
And get from high lv monsters(Twlight perion, strong hold and also the mobs in the continent that will come with 5 job), or some bosses(like you used to get book in strong bosses, like Zakum or Horntail and even Pink Bean) like Arkarium, Empress, CRA, even the Chaos bosses could drop too, not sure the rate but that's not a bad idea, the mmb could go together with it? So you can get 5 job books in two ways(three with Free Market)?
I thinked people would get 5 job at lv170, because 180 peoples have all the skills maxed, some skills would need to lose some max points(the skill max lv30 go to 20 or even 10) but in end should stay the same, and maybe you would get points until lv210; also you could get more points than normal at lv201+ since it's harder to level, and also 170~~210 are just 40 lvs(if you compare to 4 job that may have over 60 lvs or 3 job with 40 too). Nexon could do the 5 job up to 250, but it's really hard to level(i thinked they could low the total exp of lvs 201~~250 so this could be possible, like 1/10 of what is now, but since it would pineapple up with some people, i sugestest 210 firstly), would make more sense, also it would have 80 lvs.
Anything Sugest a idea about 5 job, hope you liked.
EDIT 1: i edited the image
EDIT2: if it's too much effort to nexon do the quests they can make the 5 job without quests to get the skills lv10; that's why i sugest use the same quests of the pre-big bang, but there's a lot of more classes now, so nexon will need to creat new quests anyway so just a sugestion.